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, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person *   SIERRA VENTURES VIII A, LP 2. Date of Event Requiring Statement (Month/Day/Year) 03/08/2007 3. Issuer Name and Ticker or Trading Symbol SOURCEFIRE INC [FIRE] (Last) (First) (Middle) 2884 SAND HILL ROAD, SUITE 100 4. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director __X__ 10% Owner _____ Officer (give title below) _____ Other (specify below) 5. If Amendment, Date Original Filed(Month/Day/Year) (Street) MENLO PARK, CA 94025 6. Individual or Joint/Group Filing(Check Applicable Line) ___ Form filed by One Reporting Person _X_ Form filed by More than One Reporting Person (City) (State) (Zip) 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)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.			SEC 1473 (7-02)
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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 of Derivative Security: 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
Series A Convertible Preferred Stock	  (1)	  (1)	Common Stock	2,359,607 (2)	$ (1)	I	Held by limited partnership (3) (4)
Series B Convertible Preferred Stock	  (5)	  (5)	Common Stock	1,178,464 (2)	$ (5)	I	Held by limited partnership (6) (7)
Series C Convertible Preferred Stock	  (5)	  (5)	Common Stock	831,991 (2)	$ (5)	I	Held by limited partnership (8) (9)
Series D Convertible Preferred Stock	  (5)	  (5)	Common Stock	414,130 (2)	$ (5)	I	Held by limited partnership (10) (11)

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
SIERRA VENTURES VIII A, LP 2884 SAND HILL ROAD, SUITE 100 MENLO PARK, CA 94025	Â	  X	Â	Â
SIERRA VENTURES VII LP/CA 2884 SAND HILL ROAD, SUITE 100 MENLO PARK, CA 94025	Â	  X	Â	Â
SIERRA VENTURES ASSOCIATES VII, LLC 2884 SAND HILL ROAD, SUITE 100 MENLO PARK, CA 94025	Â	  X	Â	Â
SIERRA VENTURES VIII B, LP 2884 SAND HILL ROAD, SUITE 100 MENLO PARK, CA 94025	Â	  X	Â	Â
SIERRA VENTURES ASSOCIATES VIII, LLC 2884 SAND HILL ROAD, SUITE 100 MENLO PARK, CA 94025	Â	  X	Â	Â

Signatures

/s/ Tim A. Guleri		03/08/2007
**Signature of Reporting Person		Date
/s/ David C. Schwab		03/08/2007
**Signature of Reporting Person		Date
David C. Schwab		03/08/2007
**Signature of Reporting Person		Date
/s/ Tim A. Guleri		03/08/2007
**Signature of Reporting Person		Date
/s/ Tim A. Guleri		03/08/2007
**Signature of Reporting Person		Date

Explanation of Responses:

*	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).
(1)	These securities are immediately convertible or exercisable. These securities will be automatically converted into Common Stock on a 1 to 1.84723 basis upon the closing of the Issuer?s initial public offering.
(2)	Gives effect of the conversion of the securities into Common Stock.
(3)	Includes 425,792 shares held by Sierra Ventures VII, L.P. ("Sierra VII"), 843,363 shares held by Sierra Ventures VIII-A, L.P. ("Sierra VIII-A"), 8,222 shares held by Sierra Ventures VIII-B, L.P. ("Sierra VIII-B"). Sierra Ventures Associates VII, LLC ("SVA VII") is the general partner of Sierra VII and possesses voting and dispositive power over the shares held by Sierra VII. SVA VII disclaims beneficial ownership of such shares except to the extent of its pecuniary interest therein. SVA VII also holds an additional 19,563 shares as nominee for its members. SVA VII does not have voting or dispositive power over such shares and disclaims beneficial ownership of such shares. Sierra Ventures Associates VIII, LLC ("SVA VIII") is the general partner of Sierra VIII-A and Sierra VIII-B and possesses voting and dispositive power over the shares held by Sierra VIII-A and Sierra VIII-B. (continued in next footnote)
(4)	(continued from previous footnote) SVA VIII disclaims beneficial ownership of such shares except to the extent of its pecuniary interest therein. SVA VIII also holds an additional 39,126 shares as nominee for its members. SVA VIII does not have voting or dispositive power over such shares and disclaims beneficial ownership of such shares.
(5)	These securities are immediately convertible or exercisable. These securities will be automatically converted into Common Stock on a 1 to 0.61576 basis upon the closing of the Issuer?s initial public offering.
(6)	Includes 637,883 shares held by Sierra Ventures VII, 1,263,638 shares held by Sierra Ventures VIII-A, 12,319 shares held by Sierra Ventures VIII-B, L.P. SVA VII is the general partner of Sierra VII and possesses voting and dispositive power over the shares held by Sierra VII. SVA VII disclaims beneficial ownership of such shares except to the extent of its pecuniary interest therein. SVA VII also holds an additional 47,264 shares as nominee for its members. SVA VII does not have voting or dispositive power over such shares and disclaims beneficial ownership of such shares. SVA VIII is the general partner of Sierra VIII-A and Sierra VIII-B and possesses voting and dispositive power over the shares held by Sierra VIII-A and Sierra VIII-B. SVA VIII disclaims beneficial ownership of such shares except to the extent of its pecuniary interest therein. SVA VIII also holds an additional 94,544 shares as nominee for its members. (continued in next footnote)
(7)	(continued from previous footnote) SVA VIII does not have voting or dispositive power over such shares and disclaims beneficial ownership of such shares.
(8)	Includes 455,591shares held by Sierra Ventures VII, L.P., 886,928 shares held by Sierra Ventures VIII-A, L.P., 8,646 shares held by Sierra Ventures VIII-B, L.P. SVA VII is the general partner of Sierra VII and possesses voting and dispositive power over the shares held by Sierra VII. SVA VII disclaims beneficial ownership of such shares except to the extent of its pecuniary interest therein. SVA VII also holds an additional 45,556 shares as nominee for its members. SVA VII does not have voting or dispositive power over such shares and disclaims beneficial ownership of such shares. SVA VIII is the general partner of Sierra VIII-A and Sierra VIII-B and possesses voting and dispositive power over the shares held by Sierra VIII-A and Sierra VIII-B. SVA VIII disclaims beneficial ownership of such shares except to the extent of its pecuniary interest therein. SVA VIII also holds an additional 106,871 shares as nominee for its members. (continued in next footnote)
(9)	(continued from previous footnote) SVA VIII does not have voting or dispositive power over such shares and disclaims beneficial ownership of such shares.
(10)	Includes 226,774 shares held by Sierra Ventures VII, L.P., 441,455 shares held by Sierra Ventures VIII-A, L.P., 4,324 shares held by Sierra Ventures VIII-B, L.P., SVA VII is the general partner of Sierra VII and possesses voting and dispositive power over the shares held by Sierra VII. SVA VII disclaims beneficial ownership of such shares except to the extent of its pecuniary interest therein. SVA VII also holds an additional 22,676 shares as nominee for its members. SVA VII does not have voting or dispositive power over such shares and disclaims beneficial ownership of such shares. SVA VIII is the general partner of Sierra VIII-A and Sierra VIII-B and possesses voting and dispositive power over the shares held by Sierra VIII-A and Sierra VIII-B. SVA VIII disclaims beneficial ownership of such shares except to the extent of its pecuniary interest therein. SVA VIII also holds an additional 53,196 shares as nominee for its members. (Continued in next footnote)
(11)	(continued from previous footnote) SVA VIII does not have voting or dispositive power over such shares and disclaims beneficial ownership of such shares.

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