A 19-year-old man developed paralysis of the left arm as a result of left brachial plexus injury by a traffic accident. He underwent operation for the brachial plexus paralysis, and then severe heart failure developed postoperatively. Echocardiography revealed severe tricuspid valve regurgitation. Tricuspid valve plasty was performed 14 months after the traffic accident. The anterior leaflet of the tricuspid valve was torn and the chordae attached there were torn as well. The torn anterior leaflet was sutured directly, and the prolapsed portion of this leaflet was collected by transfer of the elongated chordae. Annuloplasty (DeVega technique) was then added. Postoperative echocardiography revealed trivial regurgitation of the tricuspid valve. Only 9 cases of successful repair of traumatic tricuspid regurgitation have been reported in Japan.