In this present investigation waste chicken fat was used as a feed stock to develop the biodiesel. Two step esterification process was used to develop the biodiesel. Methanol and sulphuric acid was used in first step process and methanol and potassium hydroxide (KOH) was used in second step esterification process. Properties of the biodiesel were obtained within the ASTM standards. The effect of methanol to fat ratio and reaction time on Acid value was determined during the first step esterification and also the effect of methanol to fat ratio, reaction time and catalyst concentration on conversion efficiency was found during the second step esterification process. Low Acid value was found at 0.2 methanol to fat ratio and 600 C reaction temperature and high conversion efficiency achieved at 0.2 methanol to fat ratio, 600 C reaction temperature and 0.7% of catalyst concentration.