Fuels derived from the renewable biological resources for the use in diesel engine are known as biodiesel. Biodiesel produced from non-edible feed stocks such as Mahua, Neem, Jatropha etc. are reported to be feasible choices for developing countries like India. In this investigation the blends of varying proportions of Neem, Mahua and diesel were prepared, analyzed and compared with the performance of diesel fuel and studied using dual cylinder diesel engine at varying loads. Raw oils of Neem and Mahua were esterified (butyl esters) before blending with pure diesel. The esterified oils of biodiesel blends satisfies the important fuel properties and it lead to an improvement in engine performance and emission characteristics without any design modifications in the engine. The brake thermal efficiency, SFC, Exhaust gas temperature, Smoke density, CO, CO2 and HC were analyzed. It is observed that fuel consumption increases and brake thermal efficiency decreases as the biodiesel in the diesel blend increases. The smoke,CO,CO2 and HC emissions of the engine were increased with blends at all the loads however MB10 gives best results.