SUMMARYA case of congenital multiple rhabdomyoma of the heart in both of a set of twins of like sex is presented. A separated diamnionic dichorionic placenta was found. However because both twins had the same sex, the same color of eyes, the same blood group and very similar plantar prints pattern they were considered MZ. Twin A died after 10 days becouse of intractable heart failure. Twin B died one hour after birth of hydrops fetalis. The autopsies showed the presence of multiple rabdomyoma in the walls of both hearts and in Twin B a widely patent ductus arteriosus. No other extracardiac anomalies were noted. The diagnosis of rhabdomyoma of the heart, as is usual, was not made. It should be suspected in any infant who shows evidence of cardiac disease. On the other hand, this first case, known so far in the world literature of congenital rhabdomyoma of the heart in both twins could be an important contribution to the knowledge of the nature of this so discussed lesion.