Hereditary hemorrhagic telangiectasia (HHT) (Osler-Weber-Rendu syndrome) is a syndrome characterized by multiorgan telangiectases and arteriovenous malformations. A subset of patients with a mutation in the MADH4 gene on chromosome 18 exhibits an overlapping syndrome of HHT and juvenile polyposis (JPS). We present one such family. Genetic testing is warranted when either HHT or JPS is diagnosed, as early recognition of this syndrome overlap allows appropriate management of these patients.