The purpose of this article was to describe popliteal artery entrapment syndrome, which is a cause of intermittent claudication in a young person, and to illustrate the importance of early diagnosis for successful treatment of this entity. A case report of a 28-year-old man with popliteal artery entrapment syndrome is presented. This patient had a classic history of calf pain that worsened with walking and was relieved by rest, running, or bicycle riding. Physical examination revealed evidence of ischemia in the distal extremity, and arteriography demonstrated signs of chronic occlusive disease. Early treatment might have included surgical release of the popliteal artery and arterial grafting. Due to extensive vascular disease, grafting was not possible and a below-knee amputation was performed. It is therefore essential to diagnose popliteal artery syndrome early for appropriate management.