In the present study, the synthesis of fatty acid esters from castor oil using an alkaline catalyst was optimized. The variables were studied using a central composite design. The effects and significance of the models on the response variable and on biodiesel (methyl ester) yield derived from pure castor oil were evaluated using a response surface curve and analysis of variance. The statistical models developed from castor oil methyl ester (COME) for predicting yield showed a good agreement between the experimental and calculated response. A yield of 90.50 wt% methyl ester was achieved at 1.5 wt% KOH, 60 0C, 7:1 methanol:oil ratio and 90 min reaction time. The composition of the fatty acid methyl ester was determined by Gas Chromatography (GC). Finally, it was concluded that castor oil is distinguished by its high content of ricinoleic acid (about 89.15%), castor oil unsaturated bond, molecular weight (298), low melting point (50C), hence it gained a lot of importance in industrial applications.