In this letter, we derive an efficient audio/video synchronization method for video telephony. For synchronization, this method does not require any further RTCP packet processing except for the first one. The derived decision rule is far more compact than the conventional method. This decision rule is incorporated in an actual video telephony system adopting Texas Instruments (TI) OMAP 1510 processor and Qualcomm MSM 5500. The computational requirement was compared with the conventional method and through simulations the superiority of the proposed method is proved.