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



                                  May 20, 2004
                                  ------------
                Date of Report (Date of earliest event reported)



                                CIENA Corporation
                                -----------------
             (Exact name of registrant as specified in its charter)


          Delaware                        0-21969                 23-2725311
(State or other jurisdiction       (Commission File No.)        (IRS Employer
     of incorporation)                                       Identification No.)

                 1201 Winterson Road, Linthicum, Maryland 21090
                 ----------------------------------------------
               (Address of principal executive offices) (Zip Code)



               Registrant's telephone number, including area code:
                                 (410) 865-8500
                                 --------------


                                 Not applicable
                                 --------------
          (Former name or former address, if changed since last report)


                             Exhibit Index on Page 2



The information in this Report, including the exhibit, is furnished under Item
12 of Form 8-K and, pursuant to General Instruction B.6. thereunder, is not
"filed" for the purposes of Section 18 of the Securities Exchange Act of 1934 or
otherwise subject to the liabilities of that section. Furthermore, the
information in this Report, including the exhibit, is not incorporated by
reference into the filings of the registrant under the Securities Act of 1933.

Item 12 -- Regulation FD Disclosure (Information Provided Under Item 12 Results
of Operations and Financial Condition)

On May 20, 2004, CIENA Corporation issued a press release announcing its
financial results for the fiscal quarter ended April 30, 2004. The text of the
press release is furnished as Exhibit 99.1 to this Report.

                                      -2-


                                   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 thereunto duly authorized.




                                            CIENA CORPORATION

Dated: May 20, 2004         By: /s/ Russell B. Stevenson, Jr.
                            ---------------------------------
                            Senior Vice President, General Counsel
                            and Secretary





                                      -3-