8-K

                       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

                                  July 1, 2003
                ------------------------------------------------
                Date of report (Date of earliest event reported)

                             NetScout Systems, Inc.
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             (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
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               Registrant's telephone number, including area code

                         Exhibit Index Located on Page 5


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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 1, 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 1, 2003, NetScout issued a press release and plans to hold a
conference call on July 2, 2003 regarding its preliminary 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


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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.


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                                   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.

                                          NETSCOUT SYSTEMS, INC.

Date: July 1, 2003                        By: /s/ David P. Sommers
                                              ----------------------------------
                                              David P. Sommers
                                              Chief Financial Officer and Senior
                                              Vice President, General Operations


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                                  EXHIBIT INDEX

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

99.1          Press release dated July 1, 2003.

EX-99.1

   NetScout Announces Preliminary Results for First Quarter of Fiscal 2004

       Conference call scheduled at 8:30 AM Eastern Time, July 2, 2003

    WESTFORD, Mass., July 1 /PRNewswire-FirstCall/ --
NetScout Systems, Inc. (Nasdaq: NTCT), a leading provider of network
performance management solutions, today announced that based on preliminary
estimates it expects revenues for the first fiscal quarter, ending June 30,
2003 to be in the range of $15 to $16 million.  The GAAP net loss per share is
expected to be in the range of ($0.03) to ($0.01) and pro forma loss per share
is expected to be in the range of ($0.02) to ($0.00).  GAAP and pro forma
earnings per share include a software capitalization benefit of $0.02 after
tax per share due to post-feasibility development work on major new software
releases during the quarter.  Pro forma earnings per share exclude only stock-
based compensation of $49,000 and amortization of other intangible assets of
$272,000, totaling $321,000, which is approximately ($0.01) in earnings per
share. This compares to revenue in the previous quarter of $17.7 million, net
loss per share of ($0.01) and pro forma loss per share of ($0.00).

    "We are disappointed by the results of this quarter, which were caused by
lengthening sales cycles, driven by longer, more complex customer sign-off
processes.  However we continue to feel positive about the future," said Anil
Singhal, President and CEO of NetScout Systems.  "We expect our second fiscal
quarter to have stronger order flow, based on early indications of a stronger
sales pipeline, and bolstered by orders deferred out of the first quarter."

    "Looking beyond next quarter, we are encouraged by customer enthusiasm
with our new CDM strategy and resulting new products, presently scheduled for
release in July," Mr. Singhal added.  "We anticipate orders from the new
products will begin to impact our business in the second half of fiscal 2004.
We have been conducting extensive sales force training on the new products
over the last month which, combined with some anticipation of new product
function, may have contributed to some of the delays in the closing of sales
opportunities that we experienced at the end of this quarter."

    NetScout will hold a brief conference call tomorrow, July 2, 2003, at 8:30
a.m. ET.  NetScout plans to announce final first quarter results on July 16,
2003 after the market close.

    CONFERENCE CALL INSTRUCTIONS:

    The conference call will be webcast live through the Company's website at
http://www.netscout.com/investors.  Alternatively, people can listen to the
call by dialing 800-230-1092 for U.S./Canada and 612-332-0632 for
international callers.  A replay of the call will be available after 10:15
a.m. ET on July 2 for approximately two weeks.  The number for the replay is
800-475-6701 for U.S./Canada, and 320-365-3844 for international callers.  The
access code is 690371.

    About NetScout Systems, Inc.

    NetScout Systems, Inc. (Nasdaq: NTCT) is a market leader and pioneer of
integrated network performance management solutions for leading companies and
service providers worldwide. NetScout's offerings are based upon its
nGenius(R) Performance Management System, an integrated solution of advanced
monitoring and reporting applications that draw on the rich performance data
generated by NetScout's real-time, application-aware probes, advanced
intelligent software agents and other network devices. The nGenius System
helps organizations increase their return on infrastructure investments by
optimizing the performance of their network and applications. NetScout is
headquartered in Westford, Massachusetts and has offices in North America,
Europe and Asia. Further information on the company is available on the World
Wide Web at http://www.netscout.com.

    Safe Harbor:

    Forward-looking statements in this release are made pursuant to the safe
harbor provisions of Section 21E of the Securities Exchange Act of 1934.
Investors are cautioned that statements in this press release which are not
strictly historical statements, including the plans, objectives and future
financial performance of NetScout, constitute forward-looking statements which
involve risks and uncertainties.  Actual results could differ materially from
the forward-looking statements.  Risks and uncertainties which could cause
actual results to differ include, without limitation, risks and uncertainties
associated with the company's strategic relationships with Cisco Systems and
other partners, dependence upon broad-based acceptance of the company's
network performance management solutions, the company's ability to achieve and
maintain a high rate of growth, introduction and market acceptance of new
products and product enhancements such as the delivery of nGenius(R) product
platform probes and software solutions and the implementation of the Company's
CDM(TM) Technology strategy, the ability of NetScout to take advantage of
service provider opportunities, competitive pricing pressures, reliance on
sole source suppliers, successful expansion and management of direct and
indirect distribution channels, and dependence on proprietary technology, as
well as risks associated with a continued climate of tight IT spending, and
risks of further slowdowns or downturns in economic conditions generally and
in the market for network performance management solutions specifically.  For
a more detailed description of the risk factors associated with the company,
please refer to the company's Annual Report on Form 10-K for the fiscal year
ended March 31, 2003, on file with the Securities and Exchange Commission.
NetScout assumes no obligation to update any forward-looking information
contained in this press release or with respect to the announcements described
herein.

    In this press release we have also disclosed various non-GAAP financial
measures as defined by SEC Regulation G, including acquisition and stock-based
compensation costs.  The most directly comparable GAAP financial measures and
a reconciliation of the differences between the GAAP financial measures and
the non-GAAP financial measures can be found in the body of this press
release.

    NetScout, nGenius, and the NetScout logo are registered trademarks of
NetScout Systems, Inc., Because the network is the business and Common Data
Model (CDM) Technology are trademarks of NetScout Systems, Inc. NetScout
reserves the right, at its sole discretion, to make changes at any time in its
technical information, specifications, and service and support programs.

Contact:

Catherine Taylor
Director, Investor Relations
NetScout Systems, Inc.
Phone: 978-614-4286
Email: IR@netscout.com