A 28-year-old man presented with a chest radiograph strongly suggestive for cardiomegaly. Although he did not consent any hemodynamic studies, cardiomegaly was ruled out on the basis of the clinical course. Computed tomography showed the existence of a large mass in both sides of the heart and in both lower hemithoraces. The tumor was resected by anterior mediastinotomy; it was weighted 2100 g and measured almost 35×25×6cm. Histopathologic examination revealed thymolipoma.