UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, DC 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of

The Securities Exchange Act of 1934

Date of Report (Date of earliest event reported)

October 18, 2007

Pharsight Corporation

(Exact name of registrant as specified in its charter)

Delaware	000-31253	77-0401273
(State or other jurisdiction of incorporation)	(Commission File Number)	(IRS Employer Identification No.)

321 E. Evelyn Avenue, 3^rd Floor

Mountain View, California 94041-1530

(Address of principal executive offices, including zip code)

(650) 314-3800

(Registrant’s telephone number, including area code)

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):

¨ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

¨ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

¨ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

¨ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Item 5.03 Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year

On October 18, 2007, the Board of Directors of Pharsight Corporation (the “Company”) approved amendments to Article VII, Sections 34 and 36(a) of the Company’s Bylaws to permit the issuance and transfer of uncertificated shares of its stock. These amendments were adopted to allow the Company to participate in the direct registration system.

The foregoing description is qualified in its entirety by reference to the Certificate of Amendment of Bylaws, which is filed as Exhibit 3.1 hereto and incorporated herein by reference.

Item 9.01 Financial Statements and Exhibits

(d) Exhibits

The following exhibits are filed herewith:

Exhibit No.	Description
3.1	Certificate of Amendment of Bylaws

SIGNATURES

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

PHARSIGHT CORPORATION
By:	/s/ William Frederick
	William Frederick
	Senior Vice President and Chief Financial Officer

Date: October 23, 2007

EXHIBIT INDEX

Exhibit No.	Description
3.1	Certificate of Amendment of Bylaws