The biodiesel from edible oils is non-toxic, biodegradable and renewable alternate fuel that can be used as a substitute for diesel in diesel engines. The objective of present work is to study performance and emission characteristics of single cylinder, direct injection diesel engine with coconut oil methyl ester (COME) and blends with diesel in varying proportions. Experiments were conducted when the engine fuelled with pure diesel and the blends of diesel- COME by volume for full load range. The exhaust conditions were measured using exhaust gas analyzer similarly AVL smoke meter for measuring smoke density. Results were compared graphically in performance of the engine for specific fuel consumption, brake thermal efficiency, exhaust temperatures and in exhaust emissions for concentrations of NOx and smoke density.