Thrombosed fusiform extremity aneurysms may lead to acute arterial occlusion and can be confused with acute embolism especially in senile patients with atrial fibrillation It is important to identify the pathology with arterial doppler ultrasonography and/or computed tomography angiography preoperatively to choose the appropriate surgical method. In this article we aimed to discuss a case of giant popliteal artery aneurysm with the clinical symptoms of acute arterial occlusion and its surgical treatment.