Four of five white brothers and a son of one of them were found to have peculiar, bilateral, butterfly-shaped pigment dystrophy of the fovea. Their cases have been followed up since 1965. Three of them have normal visual acuity, and two have a slightly diminished visual acuity. Four of the five affected individuals have a pathological electro-oculogram, which reflects a diffuse abnormality of the retina. At funduscopy only two of the five affected subjects have peripheral alterations. Probably this condition is transmitted as an autosomal dominant.