SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                             ----------------------

                                   F O R M 6-K

       REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16
                    UNDER THE SECURITIES EXCHANGE ACT OF 1934

                            For the month of May 2006

                                 RADVISION LTD.
                              (Name of Registrant)


               24 Raoul Wallenberg Street, Tel Aviv 69719, Israel
                     (Address of Principal Executive Office)

                  Indicate by check mark whether the registrant files or will
file annual reports under cover of Form 20-F or Form 40-F.

                           Form 20-F [X]    Form 40-F [ ]

                  Indicate by check mark if the registrant is submitting the
Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1): [ ]

                  Indicate by check mark if the registrant is submitting the
Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7): [ ]

                  Indicate by check mark whether by furnishing the information
contained in this Form, the registrant is also thereby furnishing the
information to the Commission pursuant to Rule 12g3-2(b) under the Securities
Exchange Act of 1934.

                                 Yes [ ] No [X]

                  If "Yes" is marked, indicate below the file number assigned to
the registrant in connection with Rule 12g3-2(b): 82-___________


This Form 6-K is being incorporated by reference into the Registrant's Form S-8
Registration Statements File Nos. 333-45422, 333-53814, 333-55130, 333-66250,
333-82488, 333-104377, 333-116964 and 333-127013.





                                 RADVision Ltd.

6-K Items

     1.   Press release re RADVISION Reports  Chairman's  Purchase of Additional
          Shares dated May 18, 2006.







                                                                          ITEM 1






Press Release                                             Source: RADVISION Ltd.

RADVISION Reports Chairman's Purchase of Additional Shares

Thursday May 18, 7:00 am ET

FAIR LAWN, N.J.--(BUSINESS WIRE)--May 18, 2006--RADVISION (Nasdaq: RVSN - News),
a leading provider of multimedia conferencing, communications platforms and
development tools, reported today that Zohar Zisapel, Chairman of the Board,
purchased 194,112 shares of the Company in the open market during the week of
May 8, 2006. The total amount invested by Mr. Zisapel for those shares was
approximately $3.29 million.

Over the past 12 months, Mr. Zisapel has purchased a total of 441,150 shares of
RADVISION common stock.


Mr. Zisapel commented: "RADVISION continues to make exciting progress in
unlocking the potential of videoconferencing and video telephony - just as we
envisioned when we founded the Company in 1993. Through our focus on technology
leadership, we are advancing the development of our market as well as pursuing
our Company's growth path. I am proud of our accomplishments and see substantial
future opportunity for RADVISION."

About RADVISION

RADVISION LTD. (Nasdaq: RVSN - News) is the industry's leading provider of high
quality, scalable and easy-to-use products and technologies for
videoconferencing, video telephony, and the development of converged voice,
video and data over IP and 3G networks.  For more information please visit our
website at www.radvision.com.

This press release contains forward-looking statements that are subject to risks
and uncertainties. Factors that could cause actual results to differ materially
from these forward-looking statements include, but are not limited to, general
business conditions in the industry, changes in demand for products, the timing
and amount or cancellation of orders and other risks detailed from time to time
in RADVISION's filings with the Securities Exchange Commission, including
RADVISION's Form 20-F Annual Report. These documents contain and identify other
important factors that could cause actual results to differ materially from
those contained in our projections or forward-looking statements. Stockholders
and other readers are cautioned not to place undue reliance on these
forward-looking statements, which speak only as of the date on which they are
made. We undertake no obligation to update publicly or revise any
forward-looking statement.

Contact:
RADVISION Ltd.
Tsipi Kagan, 201-689-6340
cfo@radvision.com
or
Arnold Taragin, General Counsel, 201-689-6345
arnie@radvision.com
or
Investor Relations:
Comm-Partners LLC
June Filingeri, 203-972-0186
junefil@optonline.net




                                   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.


                                 RADVISION LTD.
                                    (Registrant)



                                 By /s/Arnold Taragin
                                    -----------------
                                    Arnold Taragin
                                    Corporate Vice President and General Counsel



Date:  May 18, 2006