SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 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): September 1, 2005

Credit Suisse First Boston Mortgage Securities Corp.
CSFB Home Equity Asset Trust 2005-6

CREDIT SUISSE FIRST BOSTON MORTGAGE SECURITIES CORP.
(Exact name of registrant as specified in its charter)
Delaware	333-120966	13-3320910
(State or Other Jurisdiction of Incorporation)	(Commission File Number)	(I.R.S. Employer Identification No.)

Eleven Madison Avenue New York, New York 10010
(Address of Principal Executive Offices) (Zip Code)

Registrant’s telephone number, including area code (212) 325-2000

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:

[ ] 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 8.01. Other Events.

McKee Nelson LLP has been retained by this Registrant as counsel for its Registration Statement on Form S-3 (Commission File No. 333-120966) in connection with various transactions. Legal opinions by McKee Nelson LLP to be incorporated into the Registration Statement are attached hereto as Exhibit 5.1, Exhibit 8.1 and Exhibit 23.1.

Item 9.01. Financial Statements and Exhibits

(a)

Not applicable.

(b)

Not applicable.

(c)

Exhibits:

5.1

Opinion of McKee Nelson LLP as to legality (including consent of such firm).

8.1

Opinion of McKee Nelson LLP as to certain tax matters (including consent of such firm included in Exhibit 5.1).

23.1

Consent of McKee Nelson LLP (included in Exhibit 5.1).

SIGNATURES

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

CREDIT SUISSE FIRST BOSTON

MORTGAGE

SECURITIES CORP.

By: /s/ Kevin Steele

Name: Kevin Steele

Title: Vice President

Dated: September 1, 2005

EXHIBIT INDEX

Exhibit No.

Description

5.1

Opinion of McKee Nelson LLP as to legality (including consent of such firm).

8.1

Opinion of McKee Nelson LLP as to certain tax matters (including consent of such firm included in Exhibit 5.1).

23.1

Consent of McKee Nelson LLP (included in Exhibit 5.1).

September 1, 2005

Credit Suisse First Boston Mortgage Securities Corp.
11 Madison Avenue
New York, New York 10010

Re:

Credit Suisse First Boston Mortgage Securities Corp.,

Registration Statement on Form S-3

Ladies and Gentlemen:

We have acted as counsel for Credit Suisse First Boston Mortgage Securities Corp., a Delaware corporation (the “Company”), in connection with the issuance of the Company’s Home Equity Pass-Through Certificates, Series 2005-6 (the “Certificates”), pursuant to a prospectus dated January 25, 2005, as supplemented by a prospectus supplement dated August 30, 2005 (the “Base Prospectus” and the “Prospectus Supplement,” respectively, and collectively the “Prospectus”). A registration statement of the Company on Form S-3 relating to the Certificates (Commission File No. 333-120966) has been filed with the Securities and Exchange Commission (the “Commission”) under the Securities Act of 1933, as amended (the “Securities Act”) and was declared effective on January 7, 2005. As set forth in the Prospectus, the Certificates will be issued under and pursuant to the conditions of a pooling and servicing agreement dated as of August 1, 2005 (the “Pooling Agreement”), among the Company, as depositor, DLJ Mortgage Capital, Inc. (“DLMC”), as a seller, Wells Fargo Bank, N.A., as a servicer (in such capacity, “WFBNA”) and Select Portfolio Servicing, Inc, as a servicer (“SPS” and together with WFBNA, the “Servicers”), U.S. Bank National Association, as trustee (the “Trustee”) and The Murrayhill Company, as credit risk manager (“Murrayhill”).

We have examined a form of the Pooling Agreement, forms of the Certificates, the Prospectus, and originals or copies, certified or otherwise identified to our satisfaction, of such instruments, certificates, records and other documents, and have made such examination of law, as we have deemed necessary or appropriate for the purpose of this opinion. In our examination, we have assumed the legal capacity of all natural persons, the genuineness of all signatures, the authenticity of all documents submitted to us as originals, the conformity to original documents of all documents submitted to us as certified or photostatic copies or by facsimile or other means of electronic transmission, and the authenticity of the originals of such latter documents. As to facts relevant to the opinions expressed herein and the other statements made herein, we have relied, to the extent we have deemed appropriate, upon certificates and oral or written statements and representations of officers and other representatives of the Company and others.

Based upon the foregoing, we are of the opinion that:

(i)

When the Pooling Agreement has been duly and validly authorized by all necessary action on the part of the Company and when the Pooling Agreement has been duly executed and delivered by the Company, DLJMC, SPS, WFBNA, the Trustee and Murrayhill and any other party thereto, the Pooling Agreement will constitute a legal, valid and binding agreement of the Company, enforceable against it in accordance with its terms, except as enforcement thereof may be limited by bankruptcy, insolvency, reorganization, moratorium, fraudulent conveyance, fraudulent transfer and other similar laws relating to or affecting creditors’ rights generally and to general equitable principles (regardless of whether considered in a proceeding in equity or at law), including concepts of commercial reasonableness, good faith and fair dealing and the possible unavailability of specific performance or injunctive relief, and with respect to the rights of indemnity or contribution, as may be limited by public policy considerations.

(ii)

When the issuance and sale of the Certificates have been duly authorized by all requisite corporate action on the part of the Company and, when duly and validly executed and authenticated in accordance with the terms of the Pooling Agreement and delivered against payment therefor pursuant to the Underwriting Agreement and Purchase Agreement, each dated as of August 30, 2005 between the Company and Credit Suisse First Boston LLC, the Certificates will be duly and validly issued and outstanding, and entitled to the benefits of the Pooling Agreement.

(iii)

Under existing law, assuming compliance with all provisions of the Pooling Agreement, for federal income tax purposes, each segregated pool of assets for which the Pooling Agreement directs that a REMIC election be made will qualify as a “real estate mortgage investment conduit” (“REMIC”) pursuant to Section 860D of the Internal Revenue Code of 1986, as amended (the “Code”); each of the Certificates, other than the Class R, Class R-II and Class A-IO-S Certificates and exclusive of the rights to receive amounts from (or the obligation to pay amounts to) the Basis Risk Reserve Fund or Supplemental Interest Trust), will evidence ownership of “regular interests” in a REMIC within the meaning of the Code; and each of the Class R Certificate and Class R-II Certificate will be considered to represent the sole class of “residual interest” in one or more REMICs within the meaning of Section 860G(a)(2) of the Code established under the Pooling Agreement.

(iv)

The statements contained under the caption “Material Federal Income Tax Consequences” in the Base Prospectus and “Material Federal Income Tax Consequences” in the Prospectus Supplement, insofar as such statements constitute conclusions of law, are true and correct in all material respects as set forth therein.

In rendering the foregoing opinions, we express no opinion as to the laws of any jurisdiction other than the federal laws of the United States of America and the laws of the State of New York.

We hereby consent to the filing of this letter and to the references to this firm under the headings “Material Federal Income Tax Consequences” and “Legal Matters” in the Base Prospectus and “Material Federal Income Tax Consequences” and “Legal Matters” in the Prospectus Supplement, without implying or admitting that we are “experts” within the meaning of the Securities Act or the rules and regulations of the Commission issued thereunder, with respect to any part of the Base Prospectus or the Prospectus Supplement.

Very truly yours,

/s/ McKee Nelson LLP

CREDIT SUISSE FIRST BOSTON MORTGAGE SECURITIES CORP 8-K