RADVISION Reports Chairman's Purchase of Additional Shares

FAIR LAWN, New Jersey, May 18, 2006 - RADVISION (Nasdaq: RVSN), 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) 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.