Forty-nine out of 51 consecutive male patients with episodic cluster headache were studied with regard to their smoking and drinking habits in general and in relation to cluster headache periods. Questionnaires were constructed for data regarding tobacco intake. Situation-related smoking behavior was registered according to Frith (1971). Screening for alcohol over-consumption was made using the Malmö modification of the brief Michigan Alcoholism Screening Test (Mm-MAST). Eighty-three percent of the patients used tobacco on a regular basis at the time of the study, with an average consumption of 20 cigarettes per day. Only 3% had never used tobacco regularly. The smoking-related desire to smoke in different situations was consistent with what is found in a general population of smokers. Sixty-seven percent of the patients had scores on the Mm-MAST indicative of alcohol over-consumption (i.e. heavy social drinking or alcoholism). During active headache periods 79% decreased their alcohol intake, whereas no consistent change in tobacco consumption was reported for the group as a whole. These findings were further corroborated by the fact that alcohol, but not tobacco intake, was reported by the majority of patients to elicit headache attacks during periods. Thus, our study showed high alcohol and tobacco consumption to be prominent features in male patients with episodic cluster headache. Since neither alcohol nor tobacco appear to have properties of ameliorating headache periods or attacks, the addictive behavior in our patients more likely reflects certain personality characteristics.