A 71-year-old male patient presented with both popliteal mass and calf claudication for 6 years. He had abruptly developed acute pain in both legs and pale skin color after interpersonal conflict. A preoperative computed tomography angiogram checked in another university hospital showed thrombosed popliteal aneurysms with acute leg ischemia in both legs. The left popliteal aneurysm was exposed with a medial approach. A thrombectomy and bypass from the proximal popliteal artery to the distal popliteal artery was done. Unfortunately the leg ischemia did not improve and below knee amputation was necessary. After transfer to Haeundae Paik Hospital, the right popliteal aneurysm was exposed with a posterior approach. After an aneurysmectomy and popliteal-peroneal bypass with peroneal endarterectomy, the leg ischemia completely resolved. He was discharged without complications. Eighteen months has passed since this operation and the patient's graft still has good patency. In the posterior approach to popliteal aneurysm, we found it possible to exposure vessels extensively including the popliteal aneurysm and it is easy to expose the distal artery. So we highly recommend the posterior approach for large popliteal aneurysm and distal artery bypass.