SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
Form N-1A
REGISTRATION STATEMENT (NO. 2-56846)
UNDER THE SECURITIES ACT OF 1933	[X]
Pre-Effective Amendment No.	[ ]
Post-Effective Amendment No. 167	[X]
and
REGISTRATION STATEMENT (NO. 811-02652) UNDER THE INVESTMENT COMPANY ACT
OF 1940
Amendment No. 168	[X]
VANGUARD INDEX FUNDS
(Exact Name of Registrant as Specified in Declaration of Trust)
P.O. Box 2600, Valley Forge, PA 19482
(Address of Principal Executive Office)
Registrant’s Telephone Number (610) 669-1000
Anne E. Robinson, Esquire
P.O. Box 876
Valley Forge, PA 19482
Approximate Date of Proposed Public Offering:
It is proposed that this filing will become effective (check appropriate box)
[X] immediately upon filing pursuant to paragraph (b)
[ ] on (date) pursuant to paragraph (b)
[ ] 60 days after filing pursuant to paragraph (a)(1)
[ ] on (date) pursuant to paragraph (a)(1)
[ ] 75 days after filing pursuant to paragraph (a)(2)
[ ] on (date) pursuant to paragraph (a)(2) of rule 485
If appropriate, check the following box:
[ ] This post-effective amendment designates a new effective date for a
previously filed post-effective amendment.

SIGNATURES
Pursuant to the requirements of the Securities Act of 1933, as amended (the Securities Act) and the Investment
Company Act of 1940, the Registrant hereby certifies that it meets all requirements for effectiveness of this
Registration Statement pursuant to Rule 485(b) under the Securities Act of 1933 and has duly caused this
Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the Town
of Valley Forge and the Commonwealth of Pennsylvania, on the 16th day of May, 2018.
	VANGUARD INDEX FUNDS
	BY:___________/s/ Mortimer J. Buckley*
		Mortimer J. Buckley
	Chief Executive Officer, President, and Trustee
Pursuant to the requirements of the Securities Act of 1933, this Post-Effective Amendment to the
Registration Statement has been signed below by the following persons in the capacities and on the date
indicated:
Signature	Title	Date
/S/ F. WILLIAM MCNABB III*	Chairman of the Board of	May 16, 2018
F. William McNabb III	Trustees
/S/ MORTIMER J. BUCKLEY*	Chief Executive Officer,	May 16, 2018
Mortimer J. Buckley	President, and Trustee
/S/ EMERSON U. FULLWOOD*	Trustee	May 16, 2018
Emerson U. Fullwood
/S/ AMY GUTMANN*	Trustee	May 16, 2018
Amy Gutmann
/S/ JOANN HEFFERNAN HEISEN*	Trustee	May 16, 2018
JoAnn Heffernan Heisen
/S/ F. JOSEPH LOUGHREY*	Trustee	May 16, 2018
F. Joseph Loughrey
/s/ MARK LOUGHRIDGE*	Trustee	May 16, 2018
Mark Loughridge
/s/ SCOTT C. MALPASS*	Trustee	May 16, 2018
Scott C. Malpass
/S/ DEANNA MULLIGAN*	Trustee	May 16, 2018
Deanna Mulligan
/S/ ANDRÉ F. PEROLD*	Trustee	May 16, 2018
André F. Perold
/S/ SARAH BLOOM RASKIN*	Trustee	May 16, 2018
Sarah Bloom Raskin
/S/ PETER F. VOLANAKIS*	Trustee	May 16, 2018
Peter F. Volanakis
/S/ THOMAS J. HIGGINS*	Chief Financial Officer	May 16, 2018
Thomas J. Higgins
*By: /s/ Anne E. Robinson
Anne E. Robinson, pursuant to a Power of Attorney filed on January 18, 2018, see file Number 33-32216,
Incorporated by Reference.

INDEX TO EXHIBITS
XBRL Instance Document	Ex-101.INS
XBRL Taxonomy Extension Schema Document	Ex-101.SCH
XBRL Taxonomy Extension Calculation Linkbase Document	Ex-101.CAL
XBRL Taxonomy Extension Definition Linkbase Document.	Ex-101.DEF
XBRL Taxonomy Extension Labels Linkbase Document	Ex-101.LAB
XBRL Taxonomy Extension Presentation Linkbase Document	Ex-101.PRE