The question has been raised whether omphalocele and gastroschisis are fundamentally different pathologic entities, or whether they are only different manifestations of the same underlying cause. After studying the family history of 37 patients with omphalocele and 14 patients with gastroschisis, it seems probable that hereditary factors contribute to the origin of omphaloceles. Such factors were not shown in patients with gastroschisis. Therefore genetic evaluation and counseling is advocated for the parents of a child with omphalocele.