The drawbacks of conventional diesel have given rise to the application of biodiesel, especially fuels derived from non-edible feed stocks. In the present study, mahua biodiesel was produced by two step esterification process involving acid esterification, reducing the FFA content from 20% to about 0.5% by addition of 3% conc. H₂SO₄ and the alkaline esterification was carried using NaOH and KOH catalysts of different amount and molar ratios. Both the catalysts yielded good results at optimum molar ratio of 6:1 and reaction temperature of 62°Cbut NaOH catalyst of 0.8%v/v yielded slightly higher quantity of biodiesel compared to 0.9% v/v KOH at 90 minutes reaction time. The fuel properties were found within the standards and GC/MS, FTIR results were satisfactory. The performance of 100% mahua biodiesel was compared to that of diesel at varying loads on a single cylinder CI engine where moderate reduction of BTE and increase of BSEC was observed. Considerable reduction of CO, HC and smoke emissions were noted along with increase in NO_x emissions.