The so-called incontinentia pigmenti achromians syndrome occurred in three children. A study of these cases together with a review of the 18 previously published cases suggests that this disease is an entity, and although some features are similar to classic incontinentia pigmenti, the differences are sufficient to separate it from this syndrome. The disease frequently involves other parts of the body including the eyes and the musculoskeletal and central nervous systems. A pattern suggestive of autosomal dominant inheritance is sometimes found. The cutaneous component is characteristic and distinguishable from systematized depigmented nevi and piebaldism. Its present name is illogical and hypomelanosis of Ito would appear to be a more suitable appellation, until the cause is better understood.