The present study was designed to explore the relationship between cigarette smoking and headache activity in a sample of patients presenting for treatment. Subjects completed various self-report measures and monitored headache activity four times per day over a 4-week period. Analyses revealed that smokers experienced greater weekly peak headache intensity, and reported higher levels of depression and general physical symptoms. Among smokers, nicotine content of the preferred brand was associated with mean headache index and weekly headache-free days, as well as depression and anxiety scores. Daily smoking rate and pack-year history were related to level of general physical symptoms only. Thus, both smoking status and the nicotine content of the preferred cigarette appear to adversely impact headache activity. Further, smokers who are more anxious or depressed may increase their headache activity via their preference for higher nicotine-content cigarettes. These results are discussed in the context of possible mechanisms underlying these effects, and implications for the clinical management of headache sufferers who smoke. Key words: cigarette smoking, headaches.