Hereditary retinoschisis affected eight members of three generations of a family. The mode of transmission and the clinical features were not compatible with findings noted in either X-chromosome-linked or autosomal recessive forms of retinoschisis. The genetic and clinical features in this family strongly supported autosomal dominant inheritance, adding to the known genetic heterogeneity for the hereditary forms of retinoschisis. The expression of the condition varied in severity, but all affected members of the family had peripheral retinoschisis and peripheral retinal degeneration. Three had maculoschisis and five had macular pigmentary changes. Electroretinographic findings were normal in six of the eight.