Prospective epidemiologic observations were made over a three-year period on children living in an area where superficial pyoderma is prevalent. Most children (81%) developed skin infection. There was no sex predilection. There was a tendency for more frequent episodes of pyoderma in children 2 to 5 years of age as compared to older children. Disease was often noted on exposed body surfaces, especially on lower extremities. Serial cultures on 15 untreated lesions indicated that spontaneous healing occurred over a range of 2 to 23 days (mean 9.6 days). Group A β-hemolytic streptococci and staphylococci were most commonly isolated organisms. These two bacterial genera coexisted in most instances; however, data are presented to suggest a primary role for streptococci and a subsidiary one for staphylococci in pathogenesis of pyoderma.