Biodiesel from non-edible vegetable oils is of paramount significance in India due to insufficient edible oil production. The present work deals with relatively underutilized non-edible oil “Schleichera oleosa” or “Kusum”. The Kusum biodiesel (KB) was produced using a two stage esterification cum transesterification process as the free fatty acid content of the oil was high. Important physico-chemical properties were evaluated and they were found to conform with corresponding ASTM/EN standards. Various test fuels were prepared for the engine trial by blending 10%, 20%, 30% and 40% of KB in diesel by volume and were named as KB10, KB20, KB30 and KB40 respectively. The results showed that full load brake thermal efficiency was dropped by 3.8% to 17% with increase in KB composition in the test fuel. Diesel (D100) showed the maximum full load brake specific energy consumption followed by KB10, KB20, KB30 and KB40. Hydrocarbons and Carbon monoxide emissions along with smoke opacity at full load were reduced by 7-42 %. However, emissions of oxides of nitrogen were found to increase marginally by 4-20% as compared to D100. Total combustion duration for KB10, KB20, KB30 and KB40 were 21, 22, 24 and 25 crank angle degrees as compared to 19 crank angles exhibited by D100. Cumulative heat release (CHR) per cycle was 1111.20, 1100.57, 1046.88, 1038.52 and 1017.62 Joules for D100, KB10, KB20, KB30 and KB40 test fuels respectively which showed continuous reduction. Ignition delay was reduced where as combustion duration as well as heat release in diffusion phase were increased for test fuel samples.