Introduction: We compared the efficacy and safety of standard heparin to that of low molecular weight heparin (Enoxaparin) in 100 hip replacement patients. Materials and methods: A total of 100 patients who underwent total hip replacement surgery were randomised to receive a study medication. Enoxaparin was administered to 50 patients (prophylaxis with subcutaneous injection of 40 mg of Enoxaparin daily was initiated 12 h preoperatively), and heparin (subcutaneous standard heparin initiated 8 h preoperatively on a dose of 5,000 IU and continued to 15,000 IU per day in three equal dosages every 8 h) was given to 50 patients. Each treatment was continued until the patients were discharged from the hospital. They were made to undergo lower extremity duplex ultrasonography for deep vein thrombosis before discharge and discontinued from medication if no pathology was found. The primary parameter to determine the efficacy was the prevalence of venous thromboembolic disease. The primary parameter to determine safety was the prevalence of major bleeding. Results: Two patients in the heparin group developed DVT, which was detected by routine duplex ultrasonography at the end of hospitalisation, and two patients in the exoparine group were detected with late DVT during the postoperative period of 6 weeks. Seven patients had minor and major bleeding in both the groups. Six patients in the heparin group discontinued from medication because of hepatic, renal dysfunctions, and serious discharges from the wound. Conclusion: Enoxaparin is as safe and as effective as standard heparin in total hip replacement surgery.