Waste Cooking Oil has recently attracted researchers and mechanical engineers as a low cost source for biodiesel production. This is because of the fact that it has a very rich oil content and eco-friendly in nature. In the present research, an orthogonal array has been used for optimizing production of biodiesel from waste cooking oil using trans-esterification process of conversion. Five independent variables were identified having impact on dependent variable yield of biodiesel(Y). Five independent variables are Stirring Speed(S), Concentration of catalyst(C), Methanol to oil ratio (M), Time of transesterification reaction (T), and working temperature (W). LP16 matrix was constructed to understand and statically examine the effects of 5 independent variables. Results of the Statistical analysis revealed that Y was maximum (74.2%) for S = 200 RPM, C = 1.60 % by Weight, M = 10:1, T = 40 Minutes and W = 328 degree Kelvin.