From 1962 through 1969, serial and longitudinal observations were made on about 500 Bantu schoolchildren aged 7 to 17 years at Komatipoort, a small country town in Eastern Transvaal, among whom 62.5 and 58.5%, respectively, were infected with Schistosoma haematobium and Schistosoma mansoni. Pupils, with those in two control schools (at Belfast, Eastern Transvaal, and at Johannesburg), were studied with respect, not only to nutrition, egg load, hematuria, and albuminuria, but also in regard to anthropometry, hematology, biochemistry, clinical state (mainly hepatomegaly and bladder calcification), physical fitness and intelligence; the various tests did not discriminate between pupils infected and not infected. We concluded that schistosomiasis of the prevalence and intensity found in the African children studied was not associated with detectable disabilities. Until further definitive studies are undertaken in regions of different endemicity, claims of deleterious effects from schistosomiasis must be treated with reserve.