OBJECTIVE To find the differences between patients with migraine with and without vertigo. METHODS A prospective study. METHODS Ambulatory dizziness centre of a tertiary referral hospital. METHODS Eighty-four patients with migraine (31 with headache, 53 with headache and vertigo) according to the diagnostic criteria of migraine published by the International Headache Society in 1988 were included in the study. Patient history, vestibular tests, electronystagmography (ENG), and imaging studies were performed for differential diagnosis. METHODS Clinical findings and ENG parameters. RESULTS Fifty-three of 84 patients (63%) had episodic vertigo attacks. Vertigo was independent from headache in 24 patients (45%). Vertigo symptoms always appeared later in the history of migraine headache. Headache started at age 27 +/- 8.3 years and vertigo symptoms began 7.7 +/- 8.7 years later. The beginning age of the migraine and female-to-male ratio were significantly greater in the vertigo group. Fifty-eight of the 84 patients had ENG testing. Fifty-eight percent of the patients with migraine and 55% of the patients with migraine + vertigo had abnormal ENG findings. None of the tests except the Dix-Hallpike manoeuvre had a statistically significant difference between the two groups. CONCLUSIONS The presence of the same ENG abnormalities in patients with pure headache shows that the vestibular pathways are also affected in these patients, even when there are no vestibular symptoms.