Intracellular proteases in three strains of sporulated Bacillus thuringiensis were identified following fractionation with ammonium sulfate. The major proteolytic activity in subsp. tenebrionis and subsp. kurstaki belonged to the metalloprotease class while in subsp. israelensis, 50 % activity was contributed by serine proteases. Protease activities in subsp. kurstaki (92 kDa, 78 kDa and 69 kDa) and subsp. israelensis (90 kDa, 75 kDa, 60 kDa and 30 kDa) were detected by gelatin SDS-PAGE.