Beef tallow, a slaughter house waste was used as a substrate for lipase production, employing Pseudomonas gessardii. The strain, P. gessardii was isolated from the beef tallow acclimatized soil. The crude lipase activity at 139U/ml by volume was obtained at optimized conditions of pH 5.0 and temperature of 37°C. After purification, a 7.59-fold purity of lipase with specific activity of 1120U/mg protein and molecular mass of 92kDa was obtained. The purified lipase showed maximum activity and stability at pH 5.0 and 30°C. Ca2+ had a stimulatory effect on the lipase activity compared to the other metal ions studied. The relative activity was enhanced with the addition of Triton X-100 with lower hydrophilic-lipophilic balance (HLB) value as 13.0 and DMSO with the lowest partition coefficient (logP) value, as 1.378. The amino acid composition and the functional groups of lipase were confirmed by HPLC and FT-IR spectroscopy. The purified lipase had the highest hydrolytic activity towards slaughterhouse wastes and vegetable oils. This work provides a potential biocatalyst for the wide applications in oleochemical and biotechnological industries. © 2010 Elsevier Ltd.