We investigated the influence of temperature, pressure, exposure time, and decompression rate on lipase activity in high-pressure CO, medium. A high-pressure, variable-volume view cell was employed in the experiments, varying the temperature from 30 to 70degreesC in the pressure range of 70-250 bar at various high-pressure exposure times (60-360 min) and adopting several decompression rates (10-200 kg/0[m(3.)min]). The results obtained show that an increase in temperature and density led to an enhancement of enzyme activity losses while the decompression rates had a weak influence on enzyme inactivation.