The authors examined and studied a family of Italian origin presenting with hereditary macular retinoschisis. Two first cousins of the third generation were affected by this disease. The mode of transmission of the pathologic gene is compatible with a recessive sex-linked heredity. The correlation between the severity of the cystic macular lesions and their functional consequences is not necessarily absolute. The lesions, which appear to be present very soon after birth, increase in severity with the years without any noticeable changes in macular function, which remains weak but stable.