A 58-year-old man was admitted with a complaint of exertional chest discomfort. A mass, 53×55×66 mm in size, was detected in the transverse sinus of the pericardium, just cranial to the inter-atrial septum with enhanced chest CT. We performed resection of the tumor under cardiopulmonary bypass. Histopathological findings showed that the tumor was angiomyolipoma originated from the heart. Angiomyolipoma is a benign tumor, most frequently found in the kidney or liver and usually associated with tuberous sclerosis. Extra-cardiac growth of the cardiac angiomyolipoma is extremely rare, and only few have been reported previously.