Right ventricular cardiomyopathy dysplasia, now a well-established clinical and morphologic entity, was first reported in the medical literature in 1982. The cases of sudden death of two young men are here reported, with macroscopic and histologic findings. The anatomical explanation of such death was a fibrotic, lipomatous, or fibrolipomatous replacement and infiltration of the myocardium of the right ventricle. It is suggested that death due to right ventricular cardiomyopathy seems to be the result of electrical instability of right ventricular myocardium. There were no congenital malformations such as septal defect or valvular deformity. The subjects’ heart weights were normal. Signs of myocardial degeneration and necrosis with or without inflammatory infiltrates were not identified.