A high step-up bridgeless single phase ac–dc power factor correction (PFC) rectifier based on Cuk topology is proposed for high voltage battery charger application. The proposed topology is designed to operate in the discontinuous conduction mode (DCM) to achieve the following advantages: simple control, high power factor, soft switching at turn on and low harmonic content of the line input current. In addition, the proposed converter exhibits low inrush current and low magnetic emission rate similar to the conventional Cuk topology. Besides, all the inductors in converter can be coupled on the same magnetic core, hence high power density is also possible. Compared to the conventional Cuk converter, the proposed bridgeless topology has lower conduction losses and higher voltage gain. Simulation and experimental results are presented along with the theoretical analysis.