The existence of Ca²⁺-dependent protease II in crude extracts of Neurospora crassa and Uromyces appendiculatus was demonstrated by immunoblotting using specific antibodies. In both extracts two immunoreacting bands were observed. The molecular mass of the major band in N. crassa corresponded to 37 kDa, while that in U. appendiculatus was 43 kDa, similar to that previously reported for Allomyces arbuscula. Immunofluorescence of the enzyme was predominantly localized in the apical regions of germlings and growing hyphae, suggesting a functional role for the enzyme in hyphal growth.