Many targets of the currently therapeutic range of the international normalized ratio anticoagulant therapy for patients with mechanical heart valves were recommended on the base of Caucasian patient groups. To the best of our knowledge it is not clear whether this therapeutic range is optimal for corresponding Chinese individuals. Methods: Between January 1996 and January 2005 inclusively, 229 patients undergoing heart-valve replacement with a mechanical device at the Tri-Service General Hospital, Taipei, were enrolled into this study. Mean patient age was 58.8±14.5 years. Various collected data pertaining to these 229 patients following aortic-valve replacement (n=87), mitral valve replacement (n=109) and double-valve replacement (n=33) with the CarboMedics prosthetic heart valve were analysed herein, and all associated complications were investigated retrospectively. Results: During the course of treatment for these 229 enrolled patients, the mean warfarin sodium dose administered was 2.81±0.75mg per day and the mean international normalized ratio value was 2.04±0.73. Perioperative mortality occurred for seven patients (3.06%), whilst major bleeding events occurred for 16 patients (1.17% per patient-year), and thromboembolism events for 14 patients (1.02% per patient-year). Conclusion: From our study, to keep international normalized ratio anticoagulant therapy above 1.5 is enough to prevent mechanical-valve associated thrombosis on Chinese patient groups.