The possible use of pre-fleshing wastes from tanneries in the production of biodiesel fuel was examimed in our previous study in 2005. In this study, engine performance and emission values of biodiesel obtained from these wastes have been investigated and compared to petrodiesel fuel. The test results demonstrated that although the wheel force and power of biodiesel fuel is slightly lower than petrodiesel and the acceleration periods are accordingly longer, the emission values of hydrocarbons and particulate matter were found to be considerably lower with biodiesel. Thus, it has been shown that a waste byproduct can be utilized in the production of an environmentally friendly fuel, which can be used in some diesel engines without a need for major adjustment, providing economic and ecological benefits. (C) 2006 Elsevier Ltd. All rights reserved.