RESUMEN
Parasitic twins are an extremely rare form of asymmetrical conjoined monochorial monoamniotic twins where one of them has a mostly intact body that is able to survive and which is referred to as 'autosite', while the counterpart, referred to as 'parasite', is only rudimentarily developed being physically attached to and nourished by the other twin. Our case is a baby boy with Single Ventricle Heart defect with a thoraco-abdominal mass (epigastric heteropagus twin) attached to the anterior abdominal wall near the umbilicus with minimal visceral sharing. The twins had two external genitalia both in host and parasite micturating separately. After high risk surgery the parasite could be separated completely from the host and postoperative recovery was uneventful.