105 patients undergoing total knee arthroplasty were included in this study to compare the efficacy of different venous thromboembolism prophylaxis techniques. Patients were randomized to one of five groups; mechanical prophylaxis, aspirin 100mg for 6 weeks, aspirin 300mg for 6 weeks, rivaroxaban 10mg for 2 weeks initiated at 24 hours or at 72 hours. The results from this study indicated no significant differences in the rate of DVT, drainage amount, hidden blood loss, the incidence fo ecchymoses and clinical outcomes. Patients in the rivaroxaban initiated at 24 hours postoperative had a greater proportion of complications compared to aspirin 100mg and the rivaroxaban initiated at 72 hours group had a greater proportion of patients receiving transfusions compared to aspirin 100mg.