SEC Form 3

FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person* van Lingen Dennis (Last) (First) (Middle) FORRESTER RESEARCH, INC. 400 TECHNOLOGY SQUARE (Street) CAMBRIDGE MA 02139 (City) (State) (Zip)	2. Date of Event Requiring Statement (Month/Day/Year) 05/15/2006	3. Issuer Name and Ticker or Trading Symbol FORRESTER RESEARCH INC [ FORR ]
		4. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director 10% Owner X Officer (give title below) Other (specify below) President, EMEA	5. If Amendment, Date of Original Filed (Month/Day/Year)
			6. Individual or Joint/Group Filing (Check Applicable Line) X Form filed by One Reporting Person Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Incentive Stock Option (right to buy)	(1)	03/30/2015	Common Stock	5,000	14.06	D
Incentive Stock Option (right to buy)	(2)	03/30/2013	Common Stock	5,000	14.73	D
Incentive Stock Option (right to buy)	(2)	03/15/2011	Common Stock	2,502	25.16	D
Non-Qualified Stock Option (right to buy)	(2)	03/15/2011	Common Stock	2,498	25.16	D
Non-Qualified Stock Option (right to buy)	(3)	09/30/2013	Common Stock	4,000	13.94	D
Non-Qualified Stock Option (right to buy)	(2)	03/30/2014	Common Stock	8,000	18.42	D
Incentive Stock Option (right to buy)	(4)	07/31/2010	Common Stock	4,896	61.25	D
Non-Qualified Stock Option (right to buy)	(4)	07/31/2010	Common Stock	104	61.25	D

Explanation of Responses:

1. The options are subject to forfeiture in the event Forrester does not achieve earnings per share ("EPS") targets established by the Compensation and Nominating Committee of the Board of Directors for fiscal 2005. If the EPS target is met, the options vest in annual increments over either two or three years from the date of grant, depending on the level of EPS achieved.

2. The Options become exercisable in four equal installments on the first, second, third, and fourth anniversaries of the grant date.

3. The Options become exercisable on the first anniversary of the grant date.

4. The Options become exercisable in three equal installments on the first, second and third anniversaries of the grant date.

Remarks:

	Kimberly A. Maxwell, attorney in fact for Dennis van Lingen	05/17/2006
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 5 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
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