Lipase (Glycerol ester hydrolase EC 3.1.1.3.) from a Brazilian strain of Fusarium solani FS1 has been investigated. The effect of different carbon sources and trace elements added to basal medium was observed with the aim of improving enzyme production. Lipase specific activity was highest (0.45 U mg(-1)) for sesame oil. When this medium was supplemented with trace elements using olive oil, corn oil and sesame oil the lipase specific activity increased to 0.86, 1.89 and 1.64 U mg(-1), respectively, after 96 h cultivation without any considerable biomass increase. The K-m of this lipase using pNPP (p-nitrophenylpalmitate) as substrate, was 1.8 mM with a V-max of 1.7 mu mol min(-1) mg protein(-1). Lipase activity increased in the presence of increasing concentrations of hexane and toluene. In contrast, incubation of this enzyme with water-soluble solvents decreased its activity after 10% concentration (v/v) of the solvent. The lipase activity was stable below 35 degrees C but above this temperature activity losses were observed.