In recent years AC-DC converters have found wide applications in industry.AC-DC converters with step down voltage are required in to be used in many applications from simple home appliances to complex industrial facilities with applications such as LED drivers, dc motor drivers, battery chargers and dc power supplies. Therefore, it is generally required that the ACDC conversion includes some form of power factor correction (PFC) so as to mitigate harmonic pollution of the grid voltage. It also requires a circuit with less number of passive elements to increase the efficiency. A Buck Bridgeless power factor correction converter with low semiconductor count is studied and analysed. The rectifier employs reduced number of semiconductor devices. Two parallel capacitors provide a path for the input current during the discharge mode to improve the current quality. Comparing with the other rectifiers this buck PFC rectifier has characteristics of high gain, high efficiency, low semiconductor devices and have few power loss. The operation principles and steady-state characteristics analysis of the rectifier is discussed in detail. Results are obtained by simulating the rectifier in MATLAB/SIMULINK R2021b. The simulation results shows that the rectifier has high voltage gain and achieves a peak efficiency of 89%. Index Terms—Buck Converter, Bridgeless, Gain, Efficiency.