The sudden development of cyanotic lesions on the feet may be a result of atheroembolic disease or a number of medical conditions. A careful history and physical examination, basic laboratory tests, and noninvasive vascular assessment usually distinguish between medical and surgical causes and direct the choice of further investigations. Specific therapy is often available for medical conditions causing this syndrome. The management of atheroembolic disease is more controversial. In particular, further research is necessary to determine which patients need surgical intervention and which patients can be managed safely by medical therapy.