Abstract
Fetus-in-fetu (FIF) is a rare condition in which malformed parasitic twin grows inside the body of its twin and usually presents as abdominal mass. We are reporting a case of neonate who presented with abdominal mass; FIF was suggestive after further radiological studies. Intra-operatively, retroperitoneal mass was identified in the sub hepatic region and successfully resected. Post operatively patient recovered well and discharged in good condition.