In the quest to reduce hazardous pollutant emissions and environmental impact, various renewable alternative fuels derived from bio-based sources have entered the market. Biodiesel, a vegetable oil ester, has gained a lot of popularity and attention for diesel engine applications. The performance of diesel engine and emission characteristics are closely linked with fuel atomization and spray pattern of fuel injection nozzles. In modern engines various orifices with different designs are used. In a diesel engine, the shape of the diesel fuel injection nozzle and the fuel flow parameters in the nozzle have a considerable impact on the processes of fuel atomization, combustion, and exhaust emissions. The main focus of this study is to explore how number of nozzle hole and shape affects the performance of diesel engine, combustion, and emissions for both Biodiesel and diesel fuels.