Objective: To evaluate the therapeutic efficacy of reversed autogenous saphenous vein bypass for thromboangiitis obliterans of the lower extremities. Methods: The clinical data of 21 patients with thromboangiitis obliterans undergoing reversed antogenous saphenous vein bypass grafting from January 2007 to May 2012 were retrospectively analyzed. Of the patients, 9 cases underwent superficial femoral-posterior tibial bypass grafting, 5 cases underwent superficial femoral-peroneal bypass grafting, 4 cases underwent superficial femoral-distal popliteal bypass grafting, and 3 cases underwent popliteal-posterior tibial bypass grafting. Results: Attempt of superficial femoral-posterior tibial bypass procedure in one patient was aborted due to inefficient outflow found at the time of surgery. The operation was accomplished in 20 patients, so the success rate was 95.2%. After surgery, the patients showed improvement of the distal blood supply of the affected leg, no rest pain, prolongation of intermittent claudication distance, and ulcer healing. The average ankle brachial index (ABI) was increased from 0.46±0.12 before surgery to 1.05±0.07 after surgery (P<0.001). Eighteen patients were followed up for 5 to 59 months with an average of (30.6±7.5) months, and the improvements in these patients were sustained. Conclusion: The reversed antogenous saphenous vein bypass is an effective treatment for thromboangiitis obliterans of the lower extremities in patients with available outflow.