Two serotypes of exfoliatin, A and B, previously reported by Kondo et al. (1974) were examined for their presence in 43 strains of Staphylococcus aureus, most of which were isolated from patients with Ritter's disease and impetigo. The tested strains consisted of 24 strains of phage group II and 19 strains not of phage group II. Twenty-four strains were found to produce an exfoliatin of either type A or type B, but 16 strains produced both types and 3 strains produced neither. No relationship was found between the serotype of an exfoliatin and the phage type of the exfoliative strain, although the single producers of exfoliatin A were all found to belong to phage group II and those of exfoliatin B to the other phage group.