Diesel engines are widely used for their low fuel consumption and better efficiency. Fuel conservation, efficiency and emission control are always the investigation points in the view of researchers in developing energy system. India to search for a suitable environmental friendly alternative to diesel fuel. The regulated emissions from diesel engines are carbon monoxide (CO), Hydrocarbons (HC), NOx and Particulate matter. It creates cancer, lungs problems, headaches and physical and mental problems of human. This paper focuses on the substitution of fossil fuel diesel with renewable alternatives fuel such as Biodiesel. Biodiesel is much clear than fossil diesel fuel and it can be used in any diesel engine without major modification. The experiment was conducted in a single-cylinder four-stroke water-cooled 3.4 kW direct injection compression ignition engine fueled with non-edible Pungamia oil biodiesel blends. The experimental results proved that up to 40% of Pungamia oil biodiesel blends give better results compared to diesel fuel. The AVL 444 di-gas analyzer and AVL 437 smoke meter are used to measure the exhaust emissions from the engine. The observation of results, non-edible Pongamia biodiesel blended fuels brake thermal efficiency (3.59%) is improved and harmful emissions like CO, unburned HC, CO2, Particulate matter, soot particles, NOx and smoke levels are 29.67%, 26.65%, 33.47%, 39.57%, +/- 3.5 and 41.03% is decreased respectively compared to the diesel fuel. This is due to biodiesel contains the inbuilt oxygen content, ignition quality, carbon burns fully, less sulphur content, no aromatics, complete CO2 cycle.