Lower-extremity arterial occlusive disease in individuals younger than 50 years is rare. We report on 4 young adults with lower limb ischemia, each of them with a different cause. According to literature premature atherosclerosis is the most common cause and is followed by thromboangiitis obliterans, coagulation abnormalities and popliteal artery entrapment syndrome. We suggest a diagnostic concept which could help to avoid undue delay.