40-17F2

EX-99

Report of Independent Registered Public Accounting Firm

To the Directors of Dreyfus Stock
Index Fund, Inc.:

We have examined management’s assertion, included in the accompanying Management Statement Regarding Compliance with Certain Provisions of the Investment Company Act of 1940, about Dreyfus Stock Index Fund, Inc.'s (the “Company”) compliance with the requirements of subsections (b) and (c) of Rule 17f-2 under the Investment Company Act of 1940 (“the Act”) as of July 31, 2006. Management is responsible for the Company’s compliance with those requirements. Our responsibility is to express an opinion on management’s assertion about the Company’s compliance based on our examination.

Our examination was conducted in accordance with the standards of the Public Company Accounting Oversight Board (United States) and, accordingly, included examining, on a test basis, evidence about the Company’s compliance with those requirements and performing such other procedures as we considered necessary in the circumstances. Included among our procedures were the following tests performed as of July 31, 2006, and with respect to agreement of security purchases and sales, for the period from May 31, 2006 (the date of the last examination), through July 31, 2006:

-	Tests of the reconciliations of security positions between Mellon Bank, N.A. (the
	"Custodian") and the Federal Reserve Bank of Boston, The Depository Trust Company and foreign sub-custodians;
-	Confirmation of securities of the Company held by the Custodian at The Depository Trust Company and the Federal Reserve Bank of Boston in book entry form;
-	Agreement of selected securities held by the Custodian at The Depository Trust Company and the Federal Reserve Bank of Boston to the omnibus account confirmations received from The Depository Trust Company and the Federal Reserve Bank of Boston;
-	Tests of the reconciliations of security positions between the books and records of the Company and the Custodian; and

-      Agreement of selected security purchases and security sales or maturities since May 31, 2006 (the date of the last examination) from the books and records of the Company to broker confirmations.

We believe that our examination provides a reasonable basis for our opinion. Our examination does not provide a legal determination on the Company’s compliance with specified requirements.

In our opinion, management’s assertion that the Company was in compliance with the requirements of subsections (b) and (c) of Rule 17f-2 of the Investment Company Act of 1940 as of July 31, 2006 with respect to securities reflected in the investment account of the Company is fairly stated, in all material respects.

This report is intended solely for the information and use of the Directors, management, and the Securities and Exchange Commission and is not intended to be and should not be used by anyone other than these specified parties.

PricewaterhouseCoopers LLP
New York, New York
December 4, 2006

2

EX-99

Management Statement Regarding Compliance with Certain Provisions of the Investment Company Act of 1940

We, as members of management of Dreyfus Stock Index Fund, Inc. (the "Company"), are responsible for complying with the requirements of subsections (b) and (c) of Rule 17f-2, Custody of Investments by Registered Management Investment Companies, of the Investment Company Act of 1940. We are also responsible for establishing and maintaining effective internal controls over compliance with those requirements. We have performed an evaluation of the Company's compliance with the requirements of subsections (b) and (c) of Rule 17f-2 as of July 31, 2006, and from May 31, 2006 through July 31, 2006.

Based on this evaluation, we assert that the Company was in compliance with the requirements of subsections (b) and (c) of Rule 17f-2 of the Investment Company Act of 1940 as of July 31, 2006, and from May 31, 2006 through July 31, 2006, with respect to securities reflected in the investment account of the Company.

Dreyfus Stock Index Fund, Inc.

By:	/s/ James Windels
	James Windels, Treasurer

Date: December 4, 2006