Hereditary hemorrhagic telangiectasia (Osler-Rendu-Weber disease) is a genetic disorder with autosomal dominance, variable penetrance, and an estimated prevalence of 1/10,000 inhabitants in France. Diagnosis is based on clinical criteria including epistaxis, telangiectasia, visceral manifestations, and familial occurrence. Pulmonary arteriovenous malformations, present in 15-33% of patients, are its primary visceral complications. The disease may be revealed by infectious and ischemic neurological manifestations due to paradoxical embolism. The high frequency of neurologic complications even in asymptomatic patients justifies systematic screening for pulmonary arteriovenous malformations. Treatment of these malformations is based on percutaneous transcatheter coil embolization of the feeding artery. Pulmonary arterial hypertension is rare in this disease. It may be due to systemic arteriovenous shunting in the liver, which increases cardiac output, or be similar to idiopathic pulmonary hypertension.