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



                                February 3, 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






TABLE OF CONTENTS Item 9 -- Information Provided Under Item 12 - -------------------------------------------- SIGNATURES - ---------- EXHIBIT INDEX - ------------- EX-99.1 Text of Press Release - ----------------------------- - ------------------------------------------------------------------------ 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 February 3, 2004, CIENA Corporation issued a press release announcing its financial results for the fiscal quarter ended January 31, 2004. The text of the press release is furnished as Exhibit 99.1 to this Report. Item 7. Financial Statements and Exhibits. (c) Exhibits -- The following exhibit is furnished as part of this Report: Exhibit 99.1 -- Text of Press Release issued by CIENA Corporation, dated February 3, 2004. -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: February 3, 2004 By: /s/ Russell B. Stevenson, Jr. --------------------------------------- Senior Vice President, General Counsel and Secretary -3-

                                                                   Exhibit 99.1

CIENA Announces Preliminary First Quarter Fiscal 2004 Results; Company
Expects to Achieve Bottom Line Guidance for Q1; Provides Outlook
Toward Second Quarter Revenue Growth

    LINTHICUM, Md.--(BUSINESS WIRE)--Feb. 3, 2004--CIENA(R)
Corporation (NASDAQ:CIEN), a leading global provider of innovative
network solutions, today announced it expects to report revenue of
approximately $66.4 million for its fiscal first quarter ended January
31, 2004, slightly below the Company's previously offered guidance
range.
    CIENA expects that under Generally Accepted Accounting Principles
(GAAP), its loss per share for the fiscal first quarter will be
reported in a range of $0.17 to $0.18.
    In evaluating the operating performance of its business, CIENA's
management excludes certain charges or credits that are required by
GAAP. These items, such as deferred stock compensation costs,
amortization of intangible assets, restructuring costs, gain or loss
on equity investments, and loss on extinguishment of debt, share one
or more of the following characteristics: they are unusual, and CIENA
does not expect them to recur in the ordinary course of its business;
they do not involve the expenditure of cash; they are unrelated to the
ongoing operation of the business in the ordinary course; or their
magnitude and timing is largely outside of the Company's control.
Exclusive of such items in its fiscal first quarter, it is expected
that CIENA's non-GAAP loss per share will be reported in a range of
$0.08 to $0.10, which would be in line with the Company's previously
offered guidance.
    "The delta between our current first quarter revenue expectations
and our previous expectations can be attributed predominantly to the
timing associated with a single order," said Gary Smith, CIENA's
president and CEO. "Although we have delivered the equipment to
fulfill this order and the customer is pleased with its performance,
it has taken longer than we anticipated to work through the
formalities and processes associated with revenue recognition.
    "We are confident we will work through these formalities in our
fiscal second quarter and while the environment remains challenging,
we currently anticipate fiscal second quarter revenue growth of up to
20% sequentially," said Smith.
    CIENA expects to report final first quarter results on Thursday,
February 19, 2004, before the open of the financial markets.

    Live Conference Call/Web Broadcast

    In conjunction with this announcement, CIENA will host a
discussion about its preliminary fiscal first quarter results with
investors and financial analysts on Tuesday, February 3, 2004 at 6:00
p.m. (Eastern). To access the call, listeners should dial (913)
981-4900 at least 10 minutes prior to the scheduled start time. No
access number or password is required. A limited number of dial-in
lines will be available. Alternatively, the discussion will be
broadcast live via CIENA's homepage at www.CIENA.com. A replay of the
call will be available by approximately 9:30 p.m. Tuesday by dialing
(719) 457-0820. Use access code 380458 for the replay only. An
archived version of the discussion also will be available shortly
following the conclusion of the live broadcast on the Investor
Relations page of CIENA's website at: www.CIENA.com/investors.

    ABOUT CIENA

    CIENA Corporation delivers innovative network solutions to the
world's largest service providers and enterprises, increasing the
cost-efficiency of current services while enabling the creation of new
carrier-class data services built upon the existing network
infrastructure. Additional information about CIENA can be found at
www.ciena.com.

    NOTE TO CIENA INVESTORS

    This press release contains certain forward-looking statements
based on current expectations, forecasts and assumptions of CIENA (the
Company) that involve risks and uncertainties. Forward-looking
statements in this release, including it expects to report revenue of
approximately $66.4 million for its fiscal first quarter ended January
31, 2004, slightly below the Company's previously offered guidance
range, CIENA expects that under Generally Accepted Accounting
Principles (GAAP), its loss per share for the fiscal first quarter
will be reported in a range of $0.17 to $0.18, exclusive of such items
in its fiscal first quarter, it is expected that CIENA's non-GAAP loss
per share will be reported in a range of $0.08 to $0.10, which would
be in line with the Company's previously offered guidance, we are
confident we will work through these formalities in our fiscal second
quarter and while the environment remains challenging, we currently
anticipate fiscal second quarter revenue growth of up to 20%
sequentially, and CIENA expects to report final first quarter results
on Thursday, February 19, 2004, before the open of the financial
markets, are based on information available to the Company as of the
date hereof. The Company's actual results could differ materially from
those stated or implied in such forward-looking statements, due to
risks and uncertainties associated with the Company's business, which
include the risk factors disclosed in the Company's Report on Form
10-K filed with the Securities and Exchange Commission on December 11,
2003. Forward-looking statements include statements regarding the
Company's expectations, beliefs, intentions or strategies regarding
the future and can be identified by forward-looking words such as
"anticipate," "believe," "could," "estimate," "expect," "intend,"
"may," "should," "will," and "would" or similar words. The Company
assumes no obligation to update the information included in this press
release, whether as a result of new information, future events or
otherwise.

    CONTACT: CIENA Corporation
             Press:
             Aaron Graham or Denny Bilter
             877-857-7377
             email: pr@ciena.com
                 or
             Investor:
             Suzanne DuLong or Jessica Towns
             888-243-6223
             email: ir@ciena.com