Depletion thread of fossil fuels and emission regularities of countries enforce researchers to use alternative resources in diesel engines. Hydrogen and biodiesel are one of the most important alternative fuels. Therefore, all effect of them must be investigated on diesel engine. In this study, experimental investigation was conducted on an unmodified four-stroke four-cylinder compression ignition engine, in order to comprehend its noise and vibration characteristics when the engine was fuelled with sunflower, canola, and corn biodiesel blends with %20 and %40 volume ratio while H-2 injected through inlet manifold with 3 l/min and 6 l/min flow rates. The results revealed that changes of sound pressure level with H-2 addition depended on engine speed whereas vibration acceleration was decreased with addition of gas at all engine speeds. Furthermore, in this paper exhaust emission characteristic of the engine when it was fuelled with sunflower, canola, and corn biodiesel blends and H-2 gas addition was presented. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.