FOR IMMEDIATE RELEASE

PLEXUS ANNOUNCES UPWARD ADJUSTMENT
TO
FISCAL 2006 FIRST QUARTER EARNINGS

Net Income now $13.7 Million and Diluted EPS $0.31

NEENAH, WI. February 6, 2006-Plexus Corp. (NASDAQ:PLXS) announced that it received payment of approximately $1.2 million on February 3, 2006 on an account that had been fully reserved when the Company issued its preliminary financial results for the fiscal first quarter ended December 31, 2005. Under U.S.-GAAP this subsequent event required a favorable adjustment in the first quarter to the Allowance for Doubtful Accounts Reserve and a consequent reduction in SG&A expense.

The after-tax impact on Net Income of this favorable adjustment is $1.2 million, or the equivalent of $0.03 per share. Accordingly, diluted EPS for the first quarter were adjusted upward from $0.28 to $0.31.

Revised summary financial statements reflecting this adjustment are attached.

About Plexus Corp. — The Product Realization Company
Plexus (www.plexus.com) is an award-winning participant in the Electronics Manufacturing Services (EMS) industry, providing product design, test, manufacturing and fulfillment and aftermarket solutions to branded product companies in the Wireline/Networking, Wireless Infrastructure, Medical, Industrial/Commercial and Defense/Security/Aerospace industries.

The Company’s unique Focused Factory manufacturing model and global supply chain solutions are strategically enhanced by value-added product design and engineering services. Plexus specializes in customer programs that require flexibility, scalability, technology and quality.

Plexus provides award-winning customer service to more than 150 branded product companies in North America, Europe and Asia.

For further information, please contact:
Gordon Bitter, CFO
920-722-3451 or email at Gordon.Bitter@Plexus.com

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PLEXUS CORP.
CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS
(in thousands, except per share data)

	Three Months Ended
	December 31,			January 1,
	2005			2005
	(unaudited)
Net sales	$	328,306		$	287,480
Cost of sales		297,031			265,185
Gross profit		31,275			22,295
Operating expenses:
Selling & administrative expenses		17,229			18,074
Restructuring and impairment costs		—			884
		17,229			18,958
Operating income		14,046			3,337
Other income (expense):
Interest expense		(830	)		(871	)
Miscellaneous		794			819
Income before income taxes		14,010			3,285
Income tax expense		253			263
Net income	$	13,757		$	3,022
Earnings per share:
Basic	$	0.31		$	0.07
Diluted	$	0.31		$	0.07
Weighted average shares outstanding:
Basic		43,897			43,191
Diluted		45,099			43,753

NON-GAAP SUPPLEMENTAL INFORMATION
(in thousands, except per share data)

	Three Months Ended
	December 31,		January 1,
	2005		2005
	(unaudited)
Net income — GAAP	$	13,757	$	3,022
Add income tax expense		253		263
Income before income taxes— GAAP		14,010		3,285
Add: Restructuring and impairment costs*		—		884
Income before income taxes and excluding restructuring and impairment costs — Non-GAAP		14,010		4,169
Income tax expense — Non-GAAP		253		334
Net income — Non-GAAP	$	13,757	$	3,835
Earnings per share — Non-GAAP:
Basic	$	0.31	$	0.09
Diluted	$	0.31	$	0.09
Weighted average shares outstanding:
Basic		43,897		43,191
Diluted		45,099		43,753
Summary of restructuring and impairment costs*
Restructuring and impairment costs:
Severance costs	$	—	$	732
Lease exit costs and other		—		28
Adjustment to asset impairment arising from a sublease of the San Diego facility		—		432
Adjustment to lease exit costs arising from a sublease of the Seattle facility		—		(308	)
Total restructuring and impairment costs	$	—	$	884

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PLEXUS CORP.
CONDENSED CONSOLIDATED BALANCE SHEETS
(in thousands, except per share data)

	December 31,		October 1,
	2005		2005
	(unaudited)
ASSETS
Current assets:
Cash and cash equivalents	$	109,667	$	98,727
Short-term investments		10,000		10,000
Accounts receivable		174,844		167,345
Inventories		183,779		180,098
Deferred income taxes		88		127
Prepaid expenses and other		5,865		5,693
Total current assets		484,243		461,990
Property, plant and equipment, net		128,686		123,140
Goodwill, net		6,790		6,995
Other		8,869		8,343
Total assets	$	628,588	$	600,468
LIABILITIES AND SHAREHOLDERS’ EQUITY
Current liabilities:
Current portion of long-term debt and capital lease obligations	$	1,758	$	770
Accounts payable		169,863		159,068
Customer deposits		8,068		7,707
Accrued liabilities:
Salaries and wages		22,651		24,052
Other		33,011		31,001
Total current liabilities		235,351		222,598
Long-term debt and capital lease obligations		21,959		22,310
Other liabilities		13,369		13,499
Deferred income taxes		1,280		2,046
Shareholders’ equity:
Common stock, $.01 par value, 200,000 shares authorized, 44,048 and 43,752 shares issued and outstanding, respectively		440		438
Additional paid-in-capital		277,443		273,419
Retained earnings		72,600		58,843
Accumulated other comprehensive income		6,146		7,315
Total shareholders’ equity		356,629		340,015
Total liabilities and shareholders’ equity	$	628,588	$	600,468

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