Fifteen patients with prolonged benign exertional headaches are described. The headaches were mostly bilateral (nine), throbbing (eight), occurring during exertion and lasting an average of four hours. Their ages at the onset of the headache varied from eight to fifty-four. In all of them, Neurological examination, neurological tests, including (CAT) computerized axial tomography, were normal. Indocin (indomethacin) completely or almost completely controlled the exertional headaches in thirteen out of fifteen patients (86%) in a period of one to four weeks. This improvement was maintained as long as the patients were taking Indocin. The entire follow-up period ranged from three to eighteen months.