A protease intended for use as a detergent additive has been studied in terms of activity as a function of temperature and stability at storage (40 ºC and 60 ºC during 15 days) and under typical washing conditions (60 ºC during 1 h) in the presence of an alkylpolyglucoside (APG), a non-ionic surfactant. Under storage at 60 ºC, the protease completely lost its activity before two days, while at 40 ºC the rate of deactivation increased with the increase in the concentration of APG. Under washing conditions the protease undergoes a complete deactivation after 60 minutes; nevertheless, the presence of the APG seems not to influence on enzyme stability. Results show that this protease is not suitable for cleaning processes at high temperatures. Furthermore, its addition to liquid detergent formulations will need a stabilization step that will ensure its activity along storage and at operation conditions.