Abstract: This paper presents an investigation on closed loop stability of SEPIC (Single-Ended Primary Inductor Converter) converter by employing an optimized PID controller where the parameters are tuned by Genetic Algorithm (GA). Genetic Algorithm is a stochastic algorithm inspired by natural evolution and is extensively used as an optimization technique in power electronics in recent years. State Space Average method is deployed to model and obtain the transfer function of the converter based system. Hence, GA based PID controller is studied and implemented in the system so that the stability of the converter can be evaluated and compared with the conventional PID controller. Different performance parameters like percentage of overshoot, rise time, settling time and peak amplitude are taken into account to investigate the stability of the system. The step responses of the closed loop system are obtained through rigorous simulation in MATLAB. Performance evaluations are obtained and tabulated to carry out the overall comparative analysis of the system.