A 44-year-old man suffered from an traffic accident on May 27, 1994. He was transferred to a hospital because of emergent operation for a laceration of liver, right-sided hemothorax and pneumothorax. After surgical treatment for these lesions, he was doing well. However, systolic murmur appeared from August, 1994. By echocardiography and cardiac catheterization, he was diagnosed of isolated tricuspid regurgitation due to traumatic ruptured papillary muscle. Because right heart failure was progressive, an operation was recommended. At operation, annular dilatation of tricuspid valve and ruptured papillary muscle of anterior leaflet were found. And the ruptured end of right ventricular aspect was recognized. Therefore, we performed tricuspid valvuloplasty and annuloplasty. Postoperative course was uneventful. And residual regurgitation was not detected by right ventriculography. Especially, in patients with tricuspid regurgitation due to ruptured papillary muscle, symptoms usually begin soon after trauma. Therefore, an operation should be recommended promptly in the presence of right heart failure not relieved by medical treatment. And an earlier operation could increase the feasibility of tricuspid valvuloplaty, and the possibility of maintaining sinus rhythm.