In situ saphenous vein graft bypass surgery is a standard procedure for infrainguinal arterial reconstruction. Since revascularization is commonly applied in below the knee region, the application of in situ saphenous vein graft bypass is becoming increasingly. We, however, recently experienced the complication of phlebitis due to unligated branches of the saphenous vein in this procedure. We here report the case and the efficacy of intraoperative angiography and postoperative ultrasound scanning to avoid such a complication.