A pedigree of familial exudative vitreoretinopathy is presented; 12 out of 37 family members examined were affected and the inheritance pattern was compatible with an autosomal dominant disease. Clinical findings and fluorescein angiographic studies of patients with the early stages of the disease support the concept that familial exudative vitreoretinopathy is a disease primarily of the small peripheral vessels leading to peripheral fibro-vascular mass lesions.