SHIP LOGO  VANGUARD(R)

                                                 P.O. Box 2600 Valley Forge,
                                                 PA 19482-2600

                                                 610-503-2398
                                                 Barry_A_Mendelson@vanguard.com


April 22, 2008


Christian Sandoe, Esq.
U.S. Securities & Exchange Commission         via electronic filing
100 F Street, N.E.
Washington, DC  20549

RE:      VANGUARD EXPLORER FUND
         FILE NO. 811-1530


Dear Mr. Sandoe,

         The following responds to your comments of April 14, 2008 on the
post-effective amendment of the registration statement of the above-referenced
registrant. You commented on Post-Effective Amendment No. 81 that was filed on
February 26, 2008.

     COMMENT: On page 37 of the prospectus, under the heading "Low Balance
Accounts," you state that the fund reserves the right to liquidate any account
whose balance falls below the minimum initial investment amount. Please clarify
that this is not the case for Admiral shareholders.

     RESPONSE:  The sentence will be rewritten to add  clarifying  language,  as
follows (new language is  capitalized):  "The Fund  reserves the right,  without
prior notice, to liquidate any investment-only  retirement-plan  fund account or
any  nonretirement  fund account whose  balance falls below the INVESTOR  SHARES
minimum initial  investment for any reason,  including  market  fluctuation." We
will make  conforming  changes to  prospectuses of other Vanguard funds over the
summer.


               *        *        *       *        *        *        *        *

     COMMENT: TANDY REQUIREMENTS
------------------------------------
As required by the SEC, the Funds acknowledge that:

                o The Fund is responsible for the adequacy and accuracy of the
                  disclosure in the filing.
                o Staff comments or changes in response to staff comments in the
                  filings reviewed by the staff do not foreclose the Commission
                  from taking any action with respect to the filing.
                o The Fund may not assert staff comments as a defense in any
                  proceeding initiated by the Commission or any person under the
                  federal securities laws of the United States.


Sincerely,



Barry A. Mendelson
Principal
The Vanguard Group, Inc.

Enclosures

cc: Christian Sandoe, Esq.
U.S. Securities and Exchange Commission