Prednisone in peak doses of 10-80 mg/day was employed for therapy in 19 patients with cluster headache. Overall, 14 of the 19 patients (73%) had greater than 50% relief and 11 (58%) had 100% relief from headache. The remaining 5 patients had less than 50% improvement. Of the subjects who were greater than 50% improved, 12 received peak doses of prednisone of 40 mg. or more, one received 30 mg. and one received 10 mg. The subjects with less than 50% improvement received peak prednisone doses of 10, 30, 40, 60 and 80 mg. Recurrence of cluster headache was noted in 79% of patients when the prednisone dose was tapered below 10–20 mg./d. Prednisone appears effective in relief of cluster headache but recurrence can be expected as the dose is reduced.