The study focuses on the production of biodiesel from waste cooking oil using the transesterification method. A maximum yield of 94% of biodiesel is achieved using transesterification method in the presence of base alkali catalyst, KOH, 0.5 wt%, at a temperature of 60 0 C and 1:06 oil: methanol ratio in 30 min at 600 rpm. Other properties such as Kinematic viscosity, flash point, acid value, %FFA, density of waste cooking oil and biodiesel are also estimated. Waste Cooking Oil being easily available and cheaper as compared to vegetable oil it is highly recommended for production of biodiesel, to be used in different applications including transportation. This will help in addressing the issues of natural resource depletion, environmental pollution and climate change.