Characterization by proteinase inhibitors of the enzymes produced by Microsporum spp. revealed that Microsporum canis and Microsporum cookei produce serine proteinase(s), but only M. canis expresses aspartic and cysteine proteinases and probably a metalloproteinase. Both M. canis and M. cookei expressed metalloelastinolytic proteinases. All the proteinase types have been implicated in the pathogenicity of a wide range of microorganisms.