In this study, the use of biodiesel as an alternative fuel synthesized from animal fat was analyzed. Different blends of biodiesel namely AFME20, AFME40 and AFME50 (by volume) were prepared and their physical properties such as kinematic viscosity, density and lower calorific value of the blends were evaluated. The experimental investigation was conducted on a single-cylinder, direct injection (DI), diesel engine at constant speed of 1500 rpm under various load conditions to study the performance, emission and combustion characteristics of various tested fuels. The results for neat diesel with different biodiesel blends suggested that brake thermal efficiency was lowered with increase in concentration of biodiesel in blends under all loading conditions. The brake specific fuel consumption was higher about 15.19%, 36.92% and 56.51% for AFME20, AFME40 and AFME50 compared to diesel fuel at maximum brake mean effective pressure. The unburned hydrocarbon, carbon monoxide and carbon soot emissions were lower for all biodiesel blends than that of diesel fuel. With increase in concentration of biodiesel in the blend, increase in formation NOx emission. The cylinder pressure and heat release rate are followed same trend for biodiesel blends compared petroleum diesel at various loading condition. © 2016, International Journal of Thermodynamics. All rights reserved.