Enzymatic activities of lipases from Chromobacterium viscosum, Pseudomonas fluorescens, Bacillus sp., Candida cylindracea, Aspergillus carneus, and Penicillium sp. were compared with the spectrophotometric p-nitrophenylbutyrate (pNB) assay at different concentrations of the detergents Tween 20, Triton X-100, polyvinyl alcohol (LALLS), and linear alkylbenzene sulfonate (LAS). The activities of lipases from C. cylindracea and C. viscosum were additionally measured with sodium desoxycholate (bile salt BL), hexadecyl trimethyl ammonium bromide (CTAB), and Tween 80. The maximal activities of eukaryotic lipases were generally at the lower concentrations of detergents than those of prokaryotic lipases. All detergents, including the anionic detergent BL, inhibited eukaryotic lipases very effectively. LAS and CTAB stimulated C. viscosum lipase above their critical micellar concentrations (CMC), but CTAB did not increase the activity of C. cylindracea lipase at all, although even a low concentration of LAS inhibited its activity. The other eukaryotic lipases behaved with LAS similarly to C. cylindracea lipase. It is more tedious to find proper detergent for eucaryotic than prokaryotic lipase, because the detergents seem to stimulate eukaryotic lipases in a very narrow range or low concentrations. Prolonged incubation with LAS decreased the activity of eukaryotic lipases effectively but prokaryotic lipases only little. LALLS could be a good detergent for the prokaryotic lipase reactions because it inhibited activity only a little. The most significant observation was the high detergent tolerance of Bacillus sp. lipase, it can be concluded that eukaryotic and prokaryotic lipases roughly Sor-m two separate classes behaving guile differently in different detergents.