Exertion induced pain of the lower limb is a common clinical problem. Different causes may lead to the clinical symptom "intermittent claudication". We differentiate vascular (peripheral arterial occlusive disease, venous occlusive disease or spinal stenosis with neurogenic claudication) and nonvascular (orthopedic, rheumatologic, neurologic) disorders. Medical history and physical examination are the cornerstone for further diagnostic procedures. We focus on peripheral arterial occlusive disease to point out how to diagnose the underlying cause of intermittent leg pain.