Hereditary haemorrhagic telangiectasia (HHT) is a genetic disorder characterized by epistaxis, telangiectasia and visceral vascular manifestations. It is associated with migraine with aura due to pulmonary arteriovenous malformations (pAVMs). The aim of the study was to evaluate headache prevalence in 106 consecutive HHT patients (67 female, 39 male, age 53.5 ± 14.5 years) and age- and gender-matched controls. An extensive clinical work-up was performed and headache prevalence was determined. Lifetime prevalence of migraine was higher in HHT patients (39.6%) than in controls (19.8%) [P < 0.001, χ2 = 12.17, odds ratio (OR) 3.0; 95% confidence interval 1.6 < OR < 5.7]. A positive association was confirmed between HHT patients with pAVMs and migraine with aura (38.5% vs. 10%). Furthermore, HHT patients without pAVMs had a higher prevalence of migraine without aura (11.5% vs. 26.3%; χ2 = 11.85; d.f. = 2; P = 0.003). We speculate that pathophysiological mechanisms, including dysfunction of the transforming growth factor-beta pathways and resulting vascular changes, contribute to the higher prevalence of migraine without aura in HHT patients without pAVMs.