A zero-voltage-switching (ZVS) bridgeless power factor correction (PFC) boost converter to reduce switching losses is proposed in this paper. Based on the conventional dual boost bridgeless converter, an auxiliary circuit including another main switch on the opposite side is added in the proposed converter to perform ZVS in man switches. Moreover, ZCS of auxiliary switches can also be achieved. As a result, the switching loss can be significantly reduced in the proposed converter. In addition, to minimize the additional conduction loss in the auxiliary circuit, the optimized design method for turn-on time of auxiliary switches is presented. The validity of the proposed converter is confirmed by the experimental results of a prototype converter with 100-240 VAC universal-line input and 800 W (400 V/2 A) output.