Biodiesel represents one of the alternative fuels to face depletion of fossil petroleum resources. In this study, combustion characteristics, performance and emissions of a diesel engine burning different blends of rapeseed ethyl ester compared to diesel fuel were evaluated. Results indicated that properties of biodiesel derived through transesterification process and its blends were within acceptable limits of standards. Biodiesel blends achieved lower thermal efficiencies as compared to diesel oil. Therefore, using ethyl esters blends results in higher specific fuel consumptions by about 1.5, 7, 13 and 17% for B5, B10, B15, and B20 in comparison to diesel fuel at full load, respectively. Smoke opacity, unburned hydrocarbons and carbon monoxide emissions of biodiesel blends were reduced but nitrogen monoxide emissions have slightly increased. Maximum cylinder pressures of biodiesel blends were lower in comparison to conventional diesel fuel. Ignition delay decreases for B5, B10, B15 and B20 at full load were 11, 19, 28 and 32 % lower than diesel fuel, respectively. Biodiesel produced from rapeseed oil could be a substitute fuel in diesel engine.