Our aim was to analyse the relationship between migraine and smoking in medical students. Medical students who had already received teaching on migraine were asked to answer an ad hoc questionnaire. A total of 361 students filled in the questionnaire: 245 (68%) were women. International Headache Society criteria were fulfilled by 58 (prevalence of migraine 16%) students. A total of 74 (20%) were current smokers: 21 males (18% of men were smokers) and 53 females (22% smokers). Within those 58 students with migraine, 17 (29%) smoke: only 2 were males (14% of males with migraine smoked) while the remaining 15 were females (34% of women with migraine smoked). Within those 17 students who were smokers and migraineurs, 12 (71%) thought that smoking worsens migraine and 10 (59%) that smoking precipitates attacks. The minimum number of cigarettes which subjectively precipitates attacks was 5. Migraine prevalence in the 20s in Spain is 16%. Our data obtained in medical students suggest that smoking can be a precipitating factor for migraine attacks, as the prevalence of active smoking is one-third higher in migraineurs and as there seems to be a relationship between the number of cigarettes and the development of migraine attacks.