N-Q

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

FORM N-Q

QUARTERLY SCHEDULE OF PORTFOLIO HOLDINGS OF REGISTERED
MANAGEMENT INVESTMENT COMPANIES

Investment Company Act file number 811- 7590

John Hancock Patriot Preferred Dividend Fund
(Exact name of registrant as specified in charter)

601 Congress Street, Boston, Massachusetts 02210
(Address of principal executive offices) (Zip code)

Alfred E. Ouellette, Senior Attorney and Assistant Secretary

601 Congress Street

Boston, Massachusetts 02210
(Name and address of agent for service)

Registrant's telephone number, including area code: 617-663-4324

Date of fiscal year end:	May 31
Date of reporting period:	August 31, 2005

ITEM 1. SCHEDULE OF INVESTMENTS

John Hancock
Patriot Preferred Dividend Fund
Securities owned by the Fund on
August 31, 2005 (unaudited)
Issuer		Shares	Value
Common stocks  13.15%			$20,770,211
(Cost $17,398,024)
Electric Utilities 3.58%			5,658,260
Alliant Energy Corp.		52,000	1,562,600
NSTAR		100,000	2,956,000
Progress Energy, Inc., (Contingent Value Obligation) (B)(I)		37,500	4,500
Xcel Energy, Inc.		59,000	1,135,160
Gas Utilities 3.21%			5,076,490
KeySpan Corp.		81,000	3,091,770
NiSource, Inc.		34,000	820,760
Peoples Energy Corp.		28,000	1,163,960
Integrated Telecommunication Services 0.56%			878,281
SBC Communications, Inc.		22,550	543,004
Verizon Communications, Inc.		10,250	335,277
Multi-Utilities & Unregulated Power 5.80%			9,157,180
Dominion Resources, Inc.		27,500	2,103,200
DTE Energy Co.		30,000	1,373,100
Sierra Pacific Resources (I)		197,000	2,872,260
TECO Energy, Inc.		62,000	1,079,420
WPS Resources Corp.		30,000	1,729,200
	Credit
Issuer, description	rating (A)	Shares	Value
Preferred stocks  85.38%			$134,833,354
(Cost $130,546,620)
Agricultural Products  3.28%			5,178,750
Ocean Spray Cranberries, Inc., 6.25%, Ser A (S)	BB+	60,000	5,178,750
Consumer Finance 4.16%			6,563,246
HSBC Finance Corp., 6.36%, Depositary Shares, Ser B	BBB+	35,600	922,396
SLM Corp., 6.97%, Ser A	BBB+	101,000	5,640,850
Diversified Banks 3.92%			6,197,760
Bank of America Corp., 6.75%, Depositary Shares, Ser VI	A	77,000	4,094,860
Royal Bank of Scotland Group Plc, 5.75%, Ser L (United Kingdom)	A	85,000	2,102,900
Diversified Chemicals 1.96%			3,101,850
Du Pont (E.I.) de Nemours & Co., $4.50, Ser B	A	33,900	3,101,850

Page 1

John Hancock
Patriot Preferred Dividend Fund
Securities owned by the Fund on
August 31, 2005 (unaudited)
Electric Utilities 14.76%			23,315,621
Alabama Power Co., 5.20%	BBB+	251,400	6,340,308
Boston Edison Co., 4.78%	BBB+	19,072	1,788,000
Duquesne Light Co., 6.50%	BB+	100,000	5,250,000
Entergy Mississippi, Inc., 6.25%	BB+	100,000	2,525,000
Interstate Power & Light Co., 7.10%, Ser C	BBB-	32,000	886,400
Northern Indiana Public Service Co., 4.88% (G)	BB+	6,925	673,673
Northern Indiana Public Service Co., 7.44%	BB+	15,150	1,556,662
Sierra Pacific Power Co., 7.80%, Ser 1 (Class A)	CCC+	110,000	2,777,500
Union Electric Co., $3.70	BBB	12,262	882,864
Wisconsin Public Service Corp., 6.76%	A-	6,095	635,214
Gas Utilities 4.60%			7,269,300
Southern Union Co., 7.55%	BB+	201,200	5,452,520
Southwest Gas Capital II, 7.70%	BB	68,300	1,816,780
Integrated Oil & Gas 3.16%			4,995,000
Coastal Finance I, 8.375%	CCC	199,800	4,995,000
Integrated Telecommunication Services 0.65%			1,030,000
Telephone & Data Systems, Inc., 6.625%	A-	40,000	1,030,000
Investment Banking & Brokerage 9.59%			15,142,355
Bear Stearns Cos., Inc. (The), 5.72%, Depositary Shares, Ser F	BBB	40,000	2,064,000
Bear Stearns Cos., Inc. (The), 6.15%, Depositary Shares, Ser E	BBB	100,600	5,361,980
Lehman Brothers Holdings, Inc., 5.67%, Depositary Shares, Ser D	BBB+	48,000	2,412,000
Lehman Brothers Holdings, Inc., 5.94%, Depositary Shares, Ser C	BBB+	102,500	5,304,375
Multi-Line Insurance 3.92%			6,196,800
MetLife, Inc., 6.50%, Ser B	BBB	240,000	6,196,800
Multi-Utilities & Unregulated Power 5.87%			9,264,772
Baltimore Gas & Electric Co., 6.99%, Ser 1995	Baa1	20,000	2,102,500
Energy East Capital Trust I, 8.25%	BBB-	168,000	4,346,160
PSEG Funding Trust II, 8.75%	BB+	30,000	822,300
Public Service Electric & Gas Co., 6.92%	BB+	19,000	1,993,812
Oil & Gas Exploration & Production 14.36%			22,668,500
Anadarko Petroleum Corp., 5.46%, Depositary Shares, Ser B	BBB-	61,489	6,100,865
Apache Corp., 5.68%, Depositary Shares, Ser B	BBB	62,200	6,377,447
Devon Energy Corp., 6.49%, Ser A	BB+	63,500	6,659,563
Nexen, Inc., 7.35% (Canada)	BB+	134,500	3,530,625
Other Diversified Financial Services 7.90%			12,469,950
Citigroup, Inc., 6.213%, Depositary Shares, Ser G	A	52,000	2,683,200
Citigroup, Inc., 6.231%, Depositary Shares, Ser H	A	88,700	4,656,750
JPMorgan Chase & Co., 6.625%, Depositary Shares, Ser H	A-	100,000	5,130,000
Regional Banks 4.38%			6,914,250
HSBC USA, Inc., $2.8575 (G)	A1	131,700	6,914,250

Page 2

John Hancock
Patriot Preferred Dividend Fund
Securities owned by the Fund on
August 31, 2005 (unaudited)
Trucking 2.87%			4,525,200
AMERCO, 8.50%, Ser A	CCC+	180,000	4,525,200
	Interest	Par value
Issuer, maturity date	rate (%)	($000)	Value
Short-term investments 1.47%			$2,318,000
(Cost $2,318,000)
Commercial Paper 1.47%			2,318,000
ChevronTexaco Corp., 09-01-05	3.380	2,318	2,318,000
Total investments 100.00%			$157,921,565

Page 3

John Hancock

Patriot Preferred Dividend Fund

Footnotes to Schedule of Investments

August 31, 2005 (unaudited)

(A)	Credit ratings are unaudited and are rated by Moody's Investors Service where Standard & Poor's ratings are not available, unless indicated otherwise.
(B)	This security is fair valued in good faith under procedures established by the Board of Trustees.
(G)	Security rated internally by John Hancock Advisers, LLC.
(I)	Non-income-producing security.
(S)	This security is exempt from registration under Rule 144A of the Securities Act of 1933. Such security may be resold, normally to qualified institutional buyers, in transactions exempt from registration.
	Rule 144A securities amounted to $5,178,750 or 3.28% of the Fund's total investments as of August 31, 2005.
	Parenthetical disclosure of a foreign country in the security description represents country of a foreign issuer.
	The percentage shown for each investment category is the total value of that category as a percentage of the total investments of the Fund.
	The cost of investments owned on August 31, 2005, including short-term investments, was $150,262,644. Gross unrealized appreciation and depreciation of investments aggregated $9,522,633 and $1,863,712, respectively, resulting in net unrealized appreciation of $7,658,921.

Footnotes to Schedule of Investments - Page 1

ITEM 2. CONTROLS AND PROCEDURES.

(a) Based upon their evaluation of the registrant's disclosure controls and procedures as conducted within 90 days of the filing date of this Form N-Q, the registrant's principal executive officer and principal accounting officer have concluded that those disclosure controls and procedures provide reasonable assurance that the material information required to be disclosed by the registrant on this report is recorded, processed, summarized and reported within the time periods specified in the Securities and Exchange Commission's rules and forms.

There were no changes in the registrant's internal control over financial reporting that occurred during the registrant's last fiscal quarter that has materially affected, or is reasonably likely to materially affect, the registrant's internal control over financial reporting.

ITEM 3. EXHIBITS.

Separate certifications for the registrant's principal executive officer and principal accounting officer, as required by Rule 30a-2(a) under the Investment Company Act of 1940, are attached.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

John Hancock Patriot Preferred Dividend Fund

By: /s/ Keith F. Hartstein
-------------------------------------
Keith F. Hartstein
President and Chief Executive Officer

Date: October 27, 2005

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated.

By: /s/ Keith F. Hartstein
-------------------------------------
Keith F. Hartstein
President and Chief Executive Officer

Date: October 27, 2005

By: /s/ John G. Vrysen
-------------------------------------
John G. Vrysen
Executive Vice President and Chief Financial Officer

Date: October 27, 2005

EX-99.CERT

CERTIFICATION

I, Keith F Hartstein, certify that:

1. I have reviewed this report on Form N-Q of John Hancock Patriot Preferred Dividend Fund (the “registrant”);

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the schedules of investments included in this report fairly present in all material respects the investments of the registrant as of the end of the fiscal quarter for which the report is filed;

4. The registrant’s other certifying officer and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act of 1940) and internal control over financial reporting (as defined in Rule 30a-3(d) under the Investment Company Act of 1940) for the registrant and have:

(a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

(b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

(c) Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of a date within 90 days prior to the filing date of this report, based on such evaluation; and

(d) Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent fiscal quarter that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5. The registrant’s other certifying officer and I have disclosed to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

(a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize, and report financial information; and

(b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date: October 27, 2005

/s/ Keith F. Hartstein
-------------------------------------
Keith F. Hartstein
President and Chief Executive Officer

CERTIFICATION

I, John G. Vrysen, certify that:

1. I have reviewed this report on Form N-Q of John Hancock Patriot Preferred Dividend Fund (the “registrant”);

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the schedules of investments included in this report fairly present in all material respects the investments of the registrant as of the end of the fiscal quarter for which the report is filed;

4. The registrant’s other certifying officer and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act of 1940) and internal control over financial reporting (as defined in Rule 30a-3(d) under the Investment Company Act of 1940) for the registrant and have:

(a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

(b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

(c) Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of a date within 90 days prior to the filing date of this report, based on such evaluation; and

(d) Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent fiscal quarter that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5. The registrant’s other certifying officer and I have disclosed to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

(a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize, and report financial information; and

(b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date: October 27, 2005

/s/ John G. Vrysen
-------------------------------------
John G. Vrysen
Executive Vice President and Chief Financial Officer