Surgical approach to the popliteal arterial aneurysm involves medial and posterior approaches. Posterior approach does not need division of hamstring muscle tendons and gastrocnemius head, which is necessary in medial approach for exposure of the entire popliteal artery (PA). Further, it has the advantage of harvesting the lesser saphenous vein without the need of additional incision. Posterior approach to vessels below PA was reported to be effective for bypass from PA to crural vessels in patients with limb ischemia. We report a case of popliteal aneurysm approached posteriorly. A 49-year-old male patient presented with a left popliteal mass and calf claudication for 2 years. Preoperative ultrasonography, MRI and angiography showed a thrombosed popliteal aneurysm. With the patient in left lateral position, the popliteal arterial aneurysm was exposed posteriorly, the lesser saphenous vein was harvested, the crural vessels were exposed by division of gastrocnemius and soleus muscles, and exclusion of the aneurysm and bypass from proximal PA to posterior tibial artery was done. Postoperatively, the patient experienced mild leg edema which soon disappeared, and he was discharged on the 23rd postoperative day. We found the posterior approach to the popliteal and proximal tibial artery to be simple and effective.