Exhibit 21.1 HARMONIC INC. AND SUBSIDIARIES SUBSIDIARIES OF THE REGISTRANT The following table shows certain information with respect to the active subsidiaries of the Company as of December 31, 2003: STATE OR OTHER PERCENT OF VOTING JURISDICTION SECURITIES OWNED NAME OF INCORPORATION BY HARMONIC - -------------------------------- ------------------ ------------------- Harmonic (Asia Pacific) Ltd. Hong Kong 100% Harmonic Data Systems Ltd. Israel 100% Harmonic Europe S.A.S. France 100% Harmonic Germany GmbH Germany 100% Harmonic International Inc. U.S.A. 100% Harmonic International Limited Bermuda 100% Harmonic Lightwaves (Israel) Ltd. Israel 100% Harmonic (UK) Ltd. United Kingdom 100%