WASHINGTON, D.C. 20549


                                    FORM 8-K

                                 CURRENT REPORT

                     PURSUANT TO SECTION 13 OR 15(D) OF THE
                         SECURITIES EXCHANGE ACT OF 1934

                                  July 16, 2003
                Date of report (Date of earliest event reported)

                             NetScout Systems, Inc.
             (Exact name of Registrant as specified in its charter)

         Delaware                        0000-26251              04-2837575
-------------------------------   ------------------------   -------------------
(State or Other Jurisdiction of   (Commission File Number)    (I.R.S. Employer
Incorporation or Organization)                               Identification No.)

                               310 Littleton Road
                          Westford, Massachusetts 01886
                    (Address of Principal Executive Offices)

                                 (978) 614-4000
               Registrant's telephone number, including area code

                         Exhibit Index Located on Page 4


Item 7. Financial Statements, Pro Forma Financial Information and Exhibits.

      (a) Financial statements of businesses acquired. Not applicable.

      (b) Pro forma financial information. Not applicable.

      (c) Exhibits.

Exhibit No.   Description
-----------   -----------

99.1          Press release dated July 16, 2003.

Item 9. Regulation FD Disclosure. (The information below is being furnished
under Item 12. Results of Operations and Financial Condition.)

      This Current Report on Form 8-K of NetScout Systems, Inc. ("NetScout") is
intended to be furnished under "Item 12. Results of Operations and Financial
Condition" but is instead furnished under "Item 9. Regulation FD Disclosure" in
accordance with Securities and Exchange Commission Release No. 33-8216. The
following information and the Exhibit attached hereto shall not be deemed
"filed" for purposes of Section 18 of the Securities Exchange Act of 1934, as
amended (the "Exchange Act") or otherwise subject to the liabilities of that
section, nor shall it be deemed incorporated by reference in any filing under
the Securities Act of 1933, as amended, or the Exchange Act, except as expressly
set forth by specific reference in such filing.

      On July 16, 2003, NetScout issued a press release and plans to hold a
conference call regarding its financial results for the quarter ended June 30,
2003. NetScout's press release is furnished as Exhibit 99.1 to this report and
is incorporated herein by reference.

Use of Non-GAAP Financial Information

      To supplement the financial measures presented in NetScout's press release
in accordance with accounting principles generally accepted in the United States
("GAAP"), NetScout also presents non-GAAP measures of net loss per share, which
are adjusted from results based on GAAP to exclude non-cash acquisition and
equity-based charges, namely costs associated with NetScout's acquisition of
NextPoint Networks, Inc. in July 2000 and costs associated with stock-based
compensation. NetScout believes these non-GAAP financial measures enhance the
user's overall understanding of NetScout's current financial performance and
NetScout's prospects for the future and, additionally, uses these non-GAAP
financial measures for the general purpose of analyzing and managing its
business. Specifically, NetScout believes the non-GAAP financial measures
provide useful information to both management and investors by excluding certain
charges that NetScout believes are not indicative of its core operating results.
In addition, NetScout believes that the investment community has historically
used its non-GAAP financial results to evaluate its financial performance, and
NetScout has historically reported both GAAP and non-GAAP results to the
investment community. The presentation of this additional information is not
meant to be considered superior to, in isolation from or as a substitute for
results prepared in accordance with GAAP.



      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.

                                          NETSCOUT SYSTEMS, INC.

Date: July 16, 2003                       By: /s/ David P. Sommers
                                              David P. Sommers
                                              Chief Financial Officer and Senior
                                              Vice President, General Operations


                                  EXHIBIT INDEX

Exhibit No.   Description
-----------   -----------

99.1          Press release dated July 16, 2003.