Simpson-Golabi-Behmel Syndrome (SGBS), an X-linked encephalo-tropho-schisis syndrome described in fewer than a dozen families, is characterized by pre- and postnatal overgrowth, "coarse" face, minor facial anomalies and, in more severe cases, multiple congenital anomalies and mental retardation. We report on 2 brothers with overgrowth, macrocephaly, polydactyly, supernumerary nipples, and characteristic facial appearance. In addition, the propositus also had pulmonic stenosis and a cleft palate. The findings present in our patients are compared to those in the original patients and to those in patients described more recently. Despite the fact that our patients have most of the minor and several of the more severe malformations, they are not mentally retarded.