Response Surface Methodology (RSM) based on a Central Composite Rotatory Design (CCRD) was used in this work to determine the optimum conditions for the transesterification of oils into biodiesel using fish oil. Three important process variables were evaluated--oil/alcohol molar ratio, reaction temperature and reaction time. A second order quadratic polynomial equation was obtained for predicting the optimisation of the transesterification reaction which was followed by experiments at the laboratory. The results obtained indicated that the parameters evaluated were the major factors affecting the yield of Biodiesel. Considering various experimental data, the optimum transesterification reaction conditions, which gave greater than 92% yield, were found to be 1:6 of oil to alcohol ratio, a reaction time of 180 minutes and a reaction temperature of 60 0 C. . The R 2 value was found to be 0.8457 indicating a high degree of correlation between the variables.