UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, DC 20549

FORM 8-K

Current Report Pursuant

to Section 13 or 15(d) of the

Securities Exchange Act of 1934

Date of Report: April 16, 2003

REDBACK NETWORKS INC.

(Exact Name of Registrant as Specified in its Charter)

Delaware	000-25853	77-0438443
(State or Other Jurisdiction of Incorporation)	(Commission File Number)	(I.R.S. Employer Identification Number)

300 Holger Way

San Jose, CA 95134

(408) 750-5000

(Addresses, including zip code, and telephone numbers, including area code, of principal executive offices)

Item 7. Financial Statements and Exhibits.

(c) Exhibits

99.1 Earnings Release dated April 16, 2003.

Item 9. Regulation FD Disclosure.

The information contained in this Item 9 of this Current Report is being furnished pursuant to “Item 12. Results of Operations and Financial Condition” of Form 8-K in accordance with SEC Release Nos. 33-8216 and 34-47583.

The information in this Current Report is being furnished and shall not be deemed “filed” for the purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that Section. The information in this Current Report shall not be incorporated by reference into any registration statement or other document pursuant to the Securities Act of 1933, as amended.

On April 16, 2003, Redback Networks Inc. issued an earnings release announcing its financial results for the first quarter ended March 31, 2003. A copy of the earnings release is attached as Exhibit 99.1.

Use of Non-GAAP Financial Information

To supplement our consolidated financial statements presented in accordance with GAAP, we use non-GAAP financial results, which are adjusted from results based on GAAP to exclude certain items. These non-GAAP results are provided to enhance the user’s overall understanding of our current financial performance and our prospects for the future. Specifically, we believe the non-GAAP results provide useful information to both management and investors by excluding certain items that we believe are not indicative of our core operating results. In addition, since we have historically reported non-GAAP results to the investment community, we believe the inclusion of non-GAAP results provides consistency in our financial reporting. Further, these non-GAAP results are one of the indicators management uses for planning and forecasting in future periods. The presentation of this additional information is not meant to be considered in isolation or as a substitute for results prepared in accordance with United States GAAP.

SIGNATURES

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

	REDBACK NETWORKS INC.
DATE: April 16, 2003	By:	/s/    THOMAS L. CRONAN III
		Thomas L. Cronan III Senior Vice President of Finance and Administration, Chief Financial Officer