A case of tricuspid regurgitation due to nonpenetrating chest trauma was presented. A 58-year-old man who had an episcde of a traffic accident 18 years ago was admitted because of the edema of the lower extremities and easy fatigability. On physical examination, engorgement of the jugular vein, enlagement of the liver and the slight edema of the lower extremities were observed. Systolic regurgitant murmur with Rivero-Carvallo sign was audible. Chest X-ray film revealed marked cardiomegaly and electrocardiogram presented atial fibrillation and complete right bundle branch block. Two-dimentional echocardiography revealed marked dilatation of the right atrium and ventricle, and systolic exertion of anterior and posterior leaflets of tricuspid valve. On cardiac catheterization, right atrial v wave was 23mm Hg. At operation, the pericardium was adheded to the epicardium, and the chorda tendae of the anterior and posterior leaflet were ruptured. Tricuspid valve replacement with 33mm Carpentier-Edwards pericardial prosthetic valve was performed without any complications. To the best of our knowledge, this is the 19th operated case of traumatic tricuspid regurgitation in Japan.