Biodiesel is a renewable fuel that is produced from vegetable oils and fat tissues. Biodiesel is mixed with diesel fuel and then is used in combustion engines. One of advantage of biodiesel is its less pollution in comparison with diesel fuels. Sound and vibration resulting from the combustion in engines have direct effects on users. One of the important properties of diesel fuels is high noise and vibration. There are a few researches on vibration of biodiesel or its blends with diesel in the world. Therefore, in this study, evaluation of vibration was performed for both biodiesel and biodiesel blends. For this, a single differential tractor including four-stroke six cylinders engine was used. It was observed that most of vibration accelerations rising are between 1800 and 2000 rpm. The mean increasing of total vibration for all fuel blends is 35.11 and 26.21 m/s(2) for this range speed, before service and serviced engine, respectively. Result showed that the total vibration values are reduced significantly after servicing the engine by 12%. Also, the vibration levels significantly are varied with the fuel blends. Statistical analysis of data showed that the vibration was lowest for B40 and B20. The results showed that the vibration of the diesel (D100) is less than biodiesel (B100). Moreover, B15, B30 and B50 had the highest vibrations. Finally at different engine speeds, vibration was always consistent with power-torque curve. (C) 2012 Elsevier Ltd. All rights reserved.