Hereditary hemorrhagic telangiectasia (Osler-Weber-Rendu syndrome) is a group of autosomal dominant diseases with variable penetration, characterized by vascular malformations. Recently hereditary hemorrhagic telangiectasia has been found to be a phenotypic expression of mutations in genes located on chromosomes 9 and 12, and possibly of other genes located on other chromosomes. We describe 2 patients with hereditary hemorrhagic telangiectasia and pulmonary involvement who presented with repeated complaints of dyspnea and cyanosis and were diagnosed as having long-standing asthma. Both were treated with therapeutic catheterization and embolization with good clinical outcomes.