Cluster headache is a defined disorder which is often mistaken in spite of its characteristic picture. The different types of cluster headache and their clinical symptoms are reviewed in detail. Predisposing factors, frequency of other medical disorders as well as personal and psychological characteristics are described. The treatment of the attack and the prophylaxis includes ergot alkaloids, methysergide, cortisone, lithium and oxygen. Some aspects of etiology and pathogenesis are discussed.