Fleshing wastes from tanneries create major environmental problems. Despite their considerable fat content, these wastes do not find important usage. Their disposal is also troublesome and costly. We have investigated the possible use of this fat in the production of biodiesel (fatty acid methyl esters) by transesterification, for use as a replacement for fossil fuels. The fat was released from the waste by boiling with water under high speed grinding, dried and used without further refining for the production of fatty acid methyl esters. Evaluation of the product indicated that it was suitable for use as a biodiesel fuel. Thus, a contaminating waste can be transformed into an environmentally friendly fuel, providing economical and ecological profits.