Migraine with aura (MA) is associated with cardiac right-to-left shunt. We prospectively studied the association between pulmonary arteriovenous malformations (PAVMs) and MA in hereditary haemorrhagic telangiectasia (HHT). All 220 consecutive HHT patients who underwent high-resolution chest computed tomography for PAVM screening were included prospectively. Prior to screening, a structured validated headache questionnaire was completed by 196 patients (57% female; mean+/-sd age 44.6+/-15.2 yrs). Two neurologists diagnosed migraine according to the International Headache Society Criteria. A PAVM was present in 70 (36%) patients. The prevalence of MA was 24% in the presence of a PAVM compared with 6% in the absence of a PAVM (OR 4.6, 95% CI 1.84-11.2; p = 0.001), and MA was an independent predictor for the presence of PAVM using multivariate analysis (OR 3.6, 95% CI 1.21-10.5; p = 0.02). A PAVM was present in 68% of the patients with MA compared with 32% in the non-migraine controls (OR 4.6, 95% CI 1.84-11.2; p = 0.001), and a PAVM was an independent predictor for MA using multivariate analysis (OR 3.0, 95% CI 1.00-9.20; p = 0.05). In conclusion, PAVMs are associated with MA in HHT patients.