The case of a patient suffering from strictly unilateral continuous headache, absolutely responsive to indomethacin is reported. This is the first Hemicrania continua case to be documented in Spain. The tyramine test resulted in anisocoria with the smaller pupil on the symptomatic side. A second tyramine test after one week on 75 mg indomethacin per day failed to produce anisocoria. Treatment was reduced to 25 mg indomethacin per day, and this dose was sufficient to control the headache completely.