Introduction: Hereditary Hemorrhagic Telangiectasia (HHT) is a rare autosomal dominant disorder causing mucocutaneous telangiectasia and arterial-venous malformations (AVMs) in various organs. Pulmonary AVMs cause right-to-left shunting, causing hypoxemia, paradoxical embolisms, and other complications. In contrast, hepatic AVMs can result in high-output heart failure due to the left-to-right shunting. About 10% of HHT patients develop pulmonary arterial hypertension (PAH), caused by small artery remodeling leading to elevated vascular resistance. This case report describes a 74-year-old woman with HHT as the cause of pulmonary hypertension, right heart failure, and anemia.