Right ventricular aneurysm (RVA) is a rare clinicopathological entity. Although it occurs as a consequence of a variety of conditions, congenital ventricular septal defect (VSD) as an etiology for the RVA has not been previously reported. A 42-year-old man without a significant family or past medical history was found dead in bed. At autopsy, the internal examination revealed a hemopericardium of 280 mL. There was a 1.5 cm diameter ruptured aneurysm of the free wall of the right ventricle. A VSD was present in the lower part of the muscular interventricular septum. The RVA was directly facing to the VSD without any obstruction in between. Microscopically the wall of the aneurysm consisted only of a thin layer of fibrous tissue transmurally with minimal interspersed cardiomyocytes. Cause of death was concluded as hemopericardium following rupture of RVA caused by a congenital VSD.