OBJECTIVE: To determine if embolization of pulmonary arteriovenous malformations (PAVMs) decreases the occurrence of migraine. METHODS: All 105 patients with hereditary hemorrhagic telangiectasia (HHT), minimum age 16 years, who underwent an embolization of PAVM in our hospital between June 1995 and April 2004, were included in this study. A structured headache questionnaire was sent to all patients and focused on two periods: 1 year before and at least 6 months after embolization. Two independent neurologists diagnosed migraine according to the International Headache Society criteria. RESULTS: Eighty-four patients (80%) sent back the questionnaire (mean age 47.8 +/- 15.1 years, 51 female). Median follow-up time was 48 months (first quartile: 23 months; third quartile: 66 months). The overall prevalence of migraine decreased from 45.2% before to 34.5% after embolization (p = 0.01). The prevalence of migraine with aura decreased from 33.3% before to 19.0% after embolization (p = 0.002). The severity of headache attacks decreased in patients who still had migraine (p = 0.15) or migraine with aura after embolization (p = 0.11). CONCLUSION: Embolization of pulmonary arteriovenous malformations in patients with hereditary hemorrhagic telangiectasia seems to be related to a decrease in prevalence of migraine, suggesting that the presence of a right-to-left shunt rather than the localization of this shunt plays a causative role in the pathogenesis of migraine.