The enzymatic hydrolysis of p-nitrophenyl laurate (PNPL) to p-nitrophenol (PNP) was studied in supercritical carbon dioxide using crude Hog Pancreas Lipase (HPL) and P roqueforti Lipase (PRL). The two enzymes were compared for their optimal activity temperatures and reaction kinetics. HPL had a higher optimal temperature (65°C) and better yield (22.5%) compared with PRL whose optimal temperature was 50°C with a 15.3% yield. This is considerably higher than the optimum temperature of 37°C and yields of less than 1% observed in the aqueous medium. © 2001 Society of Chemical Industry.