OBJECTIVES: A prospective clinical study was performed to compare the efficacy of low-molecular weight heparin and indomethacin in the prevention of deep-vein thrombosis after total knee arthroplasty in Asian patients. METHODS: One hundred fifty patients undergoing total knee arthroplasty were randomly divided into three groups. Group I (the control group) consisted of 51 patients receiving no prophylaxis with an anticoagulant. Group II consisted of 50 patients receiving the low molecular weight heparin fraxiparine, and group III consisted of 49 patients receiving indomethacin. Bilateral ascending venograms were performed preoperatively and at five to seven days postoperatively. A third venogram was performed at 3 months in patients who had had a deep vein thrombosis. RESULTS: The prevalence of deep vein thrombosis was 71% for the control group versus 50% for the fraxiparine group (p = 0.042), and 45% for the indomethacin group (p = 0.011). Deep vein thromboses were symptomatic in only 28% of the cases, and there was no pulmonary embolism. CONCLUSIONS: Fraxiparine and indomethacin significantly lowered the prevalence of deep-vein thrombosis after total knee arthroplasty as compared with the control. Prophylaxis for deep vein thrombosis in the Asian population appeared to be warranted. Furthermore, deep-vein thrombosis in the calf showed a tendency to improve with time.