Objective  Aspirin (acetylsalicylic acid, ASA) and rivaroxaban are anticoagulants that have increased in popularity due to ease of use in the prevention of venous thromboembolism (VTE) after total knee arthroplasty (TKA). The present study aimed to evaluate the efficacy of ASA compared with that of rivaroxaban on VTE prophylaxis in patients who underwent TKA. Method  Forty patients who had primary knee osteoarthritis and would undergo TKA were randomized into two groups. In total, 20 patients in the ASA group used oral aspirin, at a dose of 300 mg/day, for VTE prophylaxis after TKA, while 20 patients in the rivaroxaban group received oral rivaroxaban, at a dose of 10 mg/day. On days 4 and 14 after the operation, deep vein thrombosis (DVT) in the lower limbs on the operated side was detected through duplex ultrasonography. Other complications were recorded for 14 days. Results  There were no positive findings of DVT detected with duplex ultrasonography in the groups of patients, and the occurrence of pulmonary embolism was not observed. In total, 4 patients had subcutaneous ecchymosis on the fourth postoperative day (2 patients in the ASA group and 2 patients in the rivaroxaban group; p  = 1.0), and another 4 patients on the fourteenth postoperative day (1 patient in the ASA group and 3 patients in the rivaroxaban group; p  = 0.292). No cases of wound hematoma, major organ bleeding, wound infection, or reoperation were observed in the sample. Conclusion  Aspirin and rivaroxaban had comparable efficacy to prevent VTE, without increasing the incidence of wound complications and bleeding after TKA.