Data are scant concerning some epidemiological aspects of those severe headaches which cause serious personal and economic morbidity. Our purpose was to study the incidence and other epidemiological features of patients suffering from severe migraine exacerbations, in an unselected population. The 64 patients who suffered from severe migraine bouts represented 10.5% of all the new walk-in neurological consultations in the area covered in this study. 70% of these patients were between 10 and 39 years old. Although females clearly predominated in all ages after fifteen, below this age there was a slight male predominance. The calculated incidence of serious migraine exacerbations was 90 per 100,000 people per year, the corrected incidence for females being 143/100,000 and for males 37/100,000. The highest incidence for females was in 15–19 year-olds (377/100,000) and for males in 10–14 year-olds (166/100,000). Our data seem to confirm the periodic nature of this condition since in 80% of patients the migraine bouts (ie: groups of attacks) lasted between two and nine months. Also they support the reported existence of genetic and hormonal factors in the susceptibility to migraine exacerbations. Our results may help in planning the public health aspect of migraine and add some light to the natural history of this common condition.