Exhibit 99.1

NEWS RELEASE

CONTACTS:
Amin Khalifa, Chief Financial Officer
IRIS International, Inc.
818-527-7323

-or-

Lynn Pieper, Westwicke Partners
415-202-5678
lynn.pieper@westwicke.com

IRIS INTERNATIONAL ANNOUNCES THIRD QUARTER 2011
REVENUE AND FINANCIAL RESULTS

• Record revenue of $28.1 million; 9% growth over Q3 2010

• Gross margin of 50% in Q3 2011; Excluding Arista, gross margin of 52%

• Restructured Personalized Medicine Division by downsizing and consolidating Arista Molecular’s operations into Iris Molecular Diagnostics

• GAAP net loss per share of ($0.24); Non-GAAP diluted EPS was $0.05 per share excluding $7.6 million of one-time restructuring charges and write-downs of related assets

CHATSWORTH, Calif., November 3, 2011 — IRIS International, Inc. (NASDAQ: IRIS), a leading manufacturer of automated in-vitro diagnostics systems and consumables, and a provider of high value personalized diagnostics testing services through its CLIA certified molecular diagnostics laboratory, today announced financial results for the third quarter ended September 30, 2011.

Third Quarter 2011 Performance Highlights

• Achieved revenue of $28.1 million for the third quarter ended September 30, 2011, representing 9% growth over Q3 2010.

• Increased Iris Diagnostics Division (IDD) sales by 10% to $24.7 million as compared to $22.4 million in the prior year period.

• Realized gross margin of 50% for the third quarter 2011 compared to 51% in the prior year period. Excluding the impact from Arista in both periods, consolidated gross margin was 52%.

• Received 510(k) clearance from the FDA in September 2011 and CE Mark approval in October 2011 for its NADiA^® ProsVue™ prognostic prostate cancer test.

• NADiA ProsVue slope is indicated for use as a prognostic marker in conjunction with clinical evaluation as an aid in identifying those patients at reduced risk for recurrence of prostate cancer for the eight year period following prostatectomy. A ProsVue slope of less than 2.0 pg/ml per month in the first year following radical prostatectomy was highly associated with no evidence of disease over the long term follow up.

• NADiA ProsVue is expected to reduce unnecessary treatment of certain post-prostatectomy men thus reducing the morbidity and costs associated with adjuvant treatment such as radiation therapy.

• Completed restructuring of its Personalized Medicine division by downsizing and consolidating Arista Molecular’s operations into Iris Molecular Diagnostics. Consolidation enables significant cost reductions and enhanced profitability.

• One-time restructuring expense of $1.8 million and write-downs of related assets of $5.8 million taken in 3Q 2011.

• Arista has retained all licenses and high-complexity CLIA laboratory capabilities, as well as the necessary personnel to perform NADiA ProsVue during the early stages of product introduction. Non-proprietary testing services have been discontinued.

• Reported net loss for Q3 2011 of $4.3 million, versus net income of $0.9 million in Q3 2010. Net loss per share was ($0.24) in Q3 2011 versus diluted EPS of $0.05 in Q3 2010. Excluding charges related to the restructuring of Arista that are one time in nature, non-GAAP net income for Q3 2011 was $935,000 and non-GAAP diluted EPS was $0.05 per share, in spite of an approximate $0.7 million increase in R&D spending to fund new platforms.

“We are pleased to announce our third quarter results with record revenue reflecting strong growth in our diagnostics business. The increase in instrument sales was primarily driven by strong international demand, with consumable sales showing double-digit growth driven by our large installed base,” stated César M. García, Chairman, President and Chief Executive Officer of IRIS International.

“Additionally in the quarter, we restructured the Personalized Medicine business which we believe will result in significant expense reductions and enhanced profitability in future periods. I am particularly pleased that we also announced the FDA clearance and CE Mark approval of NADiA ProsVue. We look forward to our initial launch in 2012 and long-term commercial success of ProsVue,” Mr. García added.

“We continue to make significant progress on our 3GEMS urinalysis and hematology development programs. In October, our 3GEMS Hematology program achieved another milestone by demonstrating the integration of the complete blood count module with the imaging channel, triggering our second milestone payment from our Japanese partner. In addition, our new automated FISH platform product is on schedule to be launched in the first quarter of 2012 and is expected to reinvigorate growth in our Iris Sample Processing Division. We are achieving significant milestones in our development programs, which will further expand our product portfolio. These efforts coupled with our cost reduction initiatives are expected to drive higher revenue and earnings growth starting in 2012.”

Third Quarter 2011 Financial Results

• Consolidated revenues of $28.1 million for Q3 2011 represented growth of 9% versus Q3 2010 consolidated revenues of $25.7 million. For the third quarter ended September 30, 2011, IDD sales increased 10% year over year to $24.7 million as compared to $22.4 million in the prior year period, driven by strong growth in international instrument sales, particularly in the Asia Pacific region.

• IDD instrument sales of $7.1 million represented 5% growth over Q3 2010, driven primarily by strong international sales in the quarter. IDD consumables and service revenue of $17.5 million in Q3 2011 represented 13% growth over Q3 2010 and accounted for 62% of sales in the quarter driven primarily by our larger domestic and international installed base.

• Revenue at the Iris Sample Processing Division increased 1% to $3.4 million for Q3 2011, when compared with revenue of $3.3 million in Q3 2010.

Consolidated gross margin was 50% for the third quarter 2011 versus 51% reported for the prior period. Excluding the impact from the Arista segment, gross margin was 52% in both periods. IDD instrument gross margin improved to 37% for Q3 2011 versus 35% in Q3 2010. The increase was primarily driven by efficiency improvements related to higher production volume of iChemVELOCITY and an integrated iRICELL workstation, slightly offset by regional mix with strong international instrument sales in Q3 2011. IDD consumables and service gross margin was 57% for Q3 2011, as compared to 59% in the year ago period, the decrease primarily resulting from higher costs of Japanese sourced chemistry strips due to the appreciation of the Yen versus a year ago and an increase in service personnel to support our increasing installed base of instruments. Gross margin for the Sample Processing segment was 58% for Q3 2011 versus 54% in the prior year quarter. The increase was primarily due to favorable product mix.

The net loss for Q3 2011 was $4.3 million, versus net income of $0.9 million in Q3 2010. Excluding one-time impairment and restructuring charges in Q3 2011, non-GAAP net income was $935,000. The effective tax rate for the third quarter was 42% compared with 41% for the third quarter of 2010.

The Company’s balance sheet remains strong with cash of $19 million and no debt at September 30, 2011.

2011 Company Outlook

The company is narrowing the full year 2011 revenue guidance range to $117 — $120 million from $117 - $123 million, representing 9-11% growth over 2010. The company is maintaining non-GAAP EPS guidance $0.21 — $0.23, which excludes one-time restructuring and asset impairment charges taken in the third quarter of 2011, but reflects cost reductions in the fourth quarter as a result of the restructuring efforts.

Conference Call

IRIS International will host a conference call today at 4:30 p.m. Eastern time, 1:30 p.m. Pacific time. To participate, dial 1-877-870-9220 approximately 10 minutes before the conference call is scheduled to begin. Hold for the operator and reference the IRIS International conference call. International callers should dial 973-638-3437. The conference call may also be accessed by means of a live audio webcast on our website at http://proiris.com. The conference web cast will be archived and available for replay for 30 days from the date of the broadcast.

About IRIS International, Inc.

IRIS International, Inc. is a leading global in vitro diagnostics company focused on products that analyze particles and living cell forms and structures, or morphology of a variety of body fluids. The Company’s products leverage its strengths in flow imaging technology, particle recognition and automation to bring efficiency to hospital and commercial laboratories. The initial applications for its technology have been in the urinalysis market and the Company is the leading worldwide provider of automated urine microscopy and chemistry systems, with an installed base of more than 3,400 systems in more than 50 countries. The Company is expanding its core imaging and morphology expertise into related markets, including applications in hematology and body fluids. In addition, the Company’s personalized medicine group has a high complexity CLIA-certified laboratory for the further development and commercialization of the Company’s NADiA ultra-sensitive nucleic acid detection immunoassay platform, with applications in oncology and infectious disease. For more information, please visit www.proiris.com.

Safe Harbor Provision

This press release contains forward-looking statements made in reliance upon the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. Forward-looking statements include, but are not limited to, the Company’s views on future financial performance, market growth, capital requirements, regulatory developments, new product introductions and acquisitions, and are generally identified by phrases such as “thinks,” “anticipates,” “believes,” “estimates,” “expects,” “intends,” ,“plans,” and similar words. Forward-looking statements are not guarantees of future performance and are inherently subject to uncertainties and other factors which could cause actual results to differ materially from the forward-looking statement. These statements are based upon, among other things, assumptions made by, and information currently available to, management, including management’s own knowledge and assessment of the Company’s industry, R&D initiatives, competition and capital requirements. Other factors and uncertainties that could affect the Company’s forward-looking statements include, among other things, the following: identification of feasible new product initiatives, management of R&D efforts and the resulting successful development of new products and product platforms; obtaining regulatory approvals for new and enhanced products; acceptance by customers of the Company’s products; integration of acquired businesses; substantial expansion of international sales; reliance on key suppliers; the potential need for changes in long-term strategy in response to future developments; future advances in diagnostic testing methods and procedures; potential changes in government regulations and healthcare policies, both of which could adversely affect the economics of the diagnostic testing procedures automated by the Company’s products; rapid technological change in the microelectronics and software industries; and competitive factors, including pricing pressures and the introduction by others of new products with similar or better functionality than our products. These and other risks are more fully described in the Company’s filings with the Securities and Exchange Commission, including the Company’s most recently filed Annual Report on Form 10-K and Quarterly Report on Form 10-Q, which should be read in conjunction herewith for a further discussion of important factors that could cause actual results to differ materially from those in the forward-looking statements. The financial results presented in this press release are subject to change pending the filing of the Company’s Quarterly Report on Form 10-Q for the period ended September 30, 2011. The Company undertakes no obligation to publicly update or revise any forward-looking statements, whether as a result of new information, future events or otherwise.

Non-GAAP Financial Measures

“GAAP” refers to financial information presented in accordance with generally accepted accounting principles in the United States.

To supplement the condensed consolidated financial statements and discussion presented on a GAAP basis, this press release includes non-GAAP financial measures with respect to the three month and nine month periods ended September 30, 2011. Management uses non-GAAP financial measures because it believes the appropriate analysis of our profitability cannot be effectively considered while incorporating the effect of unusual items and charges that have not been experienced consistently in prior periods. Also, management believes these non-GAAP measures facilitate the comparison of our historical results to our competitors. The Company is reporting herein the following non-GAAP financial measures: “adjusted net income,” and “adjusted diluted earnings per share.” These non-GAAP financial measures are not in accordance with or an alternative to GAAP.

Adjusted net income excludes items which are considered unusual and the related incremental tax effect of these items. Adjusted diluted earnings per share excludes the effect of the same items described above from diluted earnings per share. Reconciliations of net income (loss), the GAAP measure most directly comparable to adjusted net income, and diluted earnings (loss) per share, the GAAP measure most directly comparable to adjusted diluted earnings per share, are provided on the attached schedule.

The presentation of historical non-GAAP financial measures is not meant to be considered in isolation from or as a substitute for results prepared in accordance with GAAP. We use these non-GAAP measures to supplement net earnings and other corresponding measures on a basis prepared in conformance with GAAP. These non-GAAP financial measures reflect additional ways of viewing aspects of our operations that when viewed with our GAAP results provide a more complete understanding of factors and trends affecting our business. However, investors should understand that the excluded items are actual expenses that may impact the cash available to us for other uses. We strongly encourage investors to consider both net earnings (loss) and cash flows determined under GAAP as compared to the non-GAAP measures presented and to perform their own analysis, as appropriate.

Reconciling Items to Non-GAAP Financial Measures

The non-GAAP measures described above exclude the following items:

a) Arista and IDD restructuring related costs — For the three and nine month periods ended September 30, 2011, we recorded restructuring related expenses of $1.8 million.

b) Arista impairment charge — For the three and nine month periods ended September 30, 2011, we recorded an impairment charge of $5.8 million related to the Arista restructuring.

(TABLES FOLLOW)
IRIS INTERNATIONAL, INC.
CONSOLIDATED BALANCE SHEETS
(in thousands)

	September 30			December 31,
	2011			2010
	(unaudited)
Assets
Current assets:
Cash and cash equivalents	$	18,858		$	25,531
Accounts receivable, net		23,264			20,733
Inventories		13,252			10,310
Prepaid expenses and other current assets		1,487			1,661
Investment in sales-type leases, current portion		3,999			3,578
Deferred tax asset		4,395			3,135
Total current assets		65,255			64,948
Property and equipment, net		13,871			12,035
Goodwill		2,451			3,957
Intangible assets, net		6,097			9,345
Software development costs, net		2,407			2,637
Deferred tax asset		2,495			2,615
Investment in sales-type leases, non-current portion		11,268			10,002
Other assets		1,262			1,070
Total assets	$	105,106		$	106,609
Liabilities and Stockholders’ Equity
Current liabilities:
Accounts payable	$	5,764		$	5,795
Accrued expenses		8,476			7,513
Deferred service contract revenue, current portion		3,849			3,205
Total current liabilities		18,089			16,513
Deferred service contract revenue, non-current portion		47			71
Other long term liabilities		55			1,374
Total liabilities		18,191			17,958
Commitments and contingencies
Stockholders’ equity:
Common stock		179			178
Preferred Stock		—			—
Additional paid-in capital		92,354			89,703
Other comprehensive income		(156	)		140
Accumulated deficit		(5,462	)		(1,370	)
Total stockholders’ equity		86,915			88,651
Total liabilities and stockholders’ equity	$	105,106		$	106,609

(More)

IRIS INTERNATIONAL, INC.
CONSOLIDATED STATEMENTS OF OPERATIONS
(unaudited — in thousands, except per share data)

	For the three months						For the nine months
	ended September 30,						ended September 30,
	2011			2010			2011			2010
Revenues
IDD instruments	$	7,147		$	6,806		$	22,772		$	22,107
IDD consumables and service		17,545			15,558			51,577			45,274
Sample processing instruments and supplies		3,358			3,335			10,638			10,986
Personalized medicine		46			27			213			27
Total revenues		28,096			25,726			85,200			78,394
Cost of Goods Sold
IDD instruments		4,474			4,447			13,836			14,194
IDD consumable and service		7,492			6,425			22,060			18,168
Sample processing instruments and supplies		1,410			1,521			4,761			4,950
Personalized medicine		572			174			1,636			174
Total cost of goods sold		13,948			12,567			42,293			37,486
Gross profit		14,148			13,159			42,907			40,908
Marketing and selling		5,635			4,956			17,590			14,152
General and administrative		4,220			4,202			14,838			12,562
Research and development, net		4,275			3,605			12,414			11,138
Impairment of assets		5,829			—			5,829			—
Restructuring expenses		1,770			—			1,770			—
Gain on revaluation of contingent consideration		—			—			(1,225	)		—
Total operating expenses		21,729			12,763			51,216			37,852
Operating income (loss)		(7,581	)		396			(8,309	)		3,056
Other income (expense):
Interest income		278			328			826			844
Interest expense		(2	)		(2	)		(8	)		(7	)
Other income (expense)		(16	)		856			397			183
Income before provision for income taxes		(7,321	)		1,578			(7,094	)		4,076
Provision for income taxes		(3,051	)		654			(3,003	)		1,486
Net income (loss)	$	(4,270	)	$	924		$	(4,091	)	$	2,590
Net income (loss) per share — basic	$	(0.24	)	$	0.05		$	(0.23	)	$	0.14
Net income (loss) per share — diluted	$	(0.24	)	$	0.05		$	(0.23	)	$	0.14
Weighted average shares outstanding — basic		17,845			17,978			17,793			17,947
Weighted average shares outstanding — diluted		17,845			18,044			17,793			18,056

(More)

IRIS INTERNATIONAL, INC.
CONSOLIDATED STATEMENTS OF CASH FLOWS
(unaudited — in thousands)

	For the nine months
	ended September 30,
	2011			2010
Cash flows from operating activities:
Net income (loss)	$	(4,091	)	$	2,590
Adjustments to reconcile net income to net cash provided by operating activities:
Loss on disposal of fixed assets		21			5
Gain on foreign currency remeasurement		(385	)		(105	)
Gain on revaluation of contingent consideration		(1,225	)		—
Deferred taxes		(1,419	)		48
Tax benefit from stock option exercises		(66	)		(48	)
Depreciation and amortization		4,027			3,084
Stock based compensation		3,103			3,193
Impairment of assets		5,829			—
Changes in operating assets and liabilities:
Accounts receivable		(2,515	)		(736	)
Inventories		(2,902	)		(1,469	)
Prepaid expenses and other current assets		(16	)		(725	)
Investment in sales-type leases		(1,677	)		(1,963	)
Accounts payable		60			280
Accrued expenses		879			1,737
Deferred service contract revenue		639			845
Other liabilities		(97	)		—
Net cash provided by operating activities		165			6,736
Cash flows from investing activities:
Purchase of assets from European distributor		—			(660	)
Acquisition of business		—			(4,630	)
Refund on acquisition of business		46			—
Acquisition of property and equipment		(6,361	)		(2,029	)
Software development costs capitalized		(419	)		(554	)
Net cash used in investing activities		(6,734	)		(7,873	)
Cash flows from financing activities:
Issuance of common stock for cash		71			31
Settlement on restricted stock tax withholding		(243	)		(239	)
Repurchase of common stock		—			(1,551	)
Tax benefit from stock option exercises		66			48
Net cash used in financing activities		(106	)		(1,711	)
Effect of exchange rate changes on cash and cash equivalents		2			(295	)
Net decrease in cash and cash equivalents		(6,673	)		(3,143	)
Cash and cash equivalents at beginning of period		25,531			34,253
Cash and cash equivalents at end of period	$	18,858		$	31,110
Supplemental schedule of non-cash financing activities:
During the nine months ended September 30, 2011, the Company disposed of property and equipment with a cost and accumulated depreciation of $498 and $477, respectively.
Supplemental disclosure of cash flow information:
Cash paid for income taxes	$	1,231		$	2,066
Cash paid for interest	$	8		$	7

IRIS INTERNATIONAL, INC.
RECONCILIATION OF GAAP NET LOSS AND NET LOSS PER SHARE TO ADJUSTED
NET INCOME AND ADJUSTED DILUTED EARNINGS PER SHARE
(unaudited — in thousands, except per share data)

	For the three months									For the nine months
	ended September 30, 2011									ended September 30, 2011
	Pretax			After tax			Per diluted			Pretax			After tax			Per diluted
	amount			amount(1)(2)			share			amount			amount			share
GAAP net loss & net loss per share	$	(7,321	)	$	(4,270	)	$	(0.24	)	$	(7,094	)	$	(4,091	)	$	(0.23	)
Reconciling items:
Restructuring expenses		1,770			1,080			0.06			1,770			1,080			0.06
Impairment charge (excluding Goodwill)		4,369			2,665			0.15			4,369			2,665			0.15
Goodwill impairment (1)		1,460			1,460			0.08			1,460			1,460			0.08
Adjusted net income & diluted EPS (3)	$	278		$	935		$	0.05		$	505		$	1,114		$	0.06

(1)	Goodwill is not tax affected
(2)	Reconciling items taxed at statutory rate of 39%
(3)	Amounts may not foot due to rounding.

See accompanying Non-GAAP Financial Measures section for description of Non-GAAP adjustments.

# # #