UNITED STATES

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)

June 1, 2006

CSMC Mortgage-Backed Trust Series 2006-5

(Issuing Entity)

Credit Suisse First Boston Mortgage Securities Corp.

(Exact Name of Depositor as Specified in its Charter)

DLJ Mortgage Capital, Inc.

(Exact Name of Sponsor as Specified in its Charter)

Credit Suisse First Boston Mortgage Securities Corp.

(Exact Name of Registrant as Specified in its Charter)

Delaware

333-130884

13-3320910

(State or Other Jurisdiction

Of Incorporation)

(Commission

File Number)

(I.R.S. Employer

Identification No.)

11 Madison Avenue

New York, NY

10010

(Address of Principal Executive Offices)

(Zip Code)

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

No Change

(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:

[ ] 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 9.01.

Financial Statements, Pro Forma Financial.

Filing of Computational Materials

Pursuant to Rule 424(b) under the Securities Act of 1933, concurrently with, or subsequent to, the filing of this Current Report on Form 8-K (the “Form 8-K”), Credit Suisse First Boston Mortgage Securities Corp. (the “Company”) is filing a prospectus and prospectus supplement with the Securities and Exchange Commission relating to its Credit Suisse First Boston Mortgage Securities Corp., CSMC Mortgage-Backed Pass-Through Certificates, Series 2006-5.

In connection with the offering of the CSMC Mortgage-Backed Pass-Through Certificates, Series 2006-5, Credit Suisse Securities (USA) LLC (“Credit Suisse”), as underwriter of the Certificates, has prepared certain materials (the “Computational Materials”) for distribution to their potential investors. Although the Company provided Credit Suisse with certain information regarding the characteristics of the Mortgage Loans in the related portfolio, the Company did not participate in the preparation of the Computational Materials.

For purposes of this Form 8-K, “Computational Materials” shall mean computer generated tables and/or charts displaying, with respect to any Class or Classes of Certificates, any of the following: yield; average life; duration; expected maturity; interest rate sensitivity; loss sensitivity; cash flow characteristics; background information regarding the Mortgage Loans; the proposed structure; decrement tables; or similar information (tabular or otherwise) of a statistical, mathematical, tabular or computational nature.

The Computational Materials are attached hereto as Exhibit 99.1.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant 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: Director

Dated: June 1, 2006

Exhibit Index

Exhibit

Page

99.1

Computational Materials

CSMC Mortgage-Backed Trust Series 2006-5 8-K