Hereditary hemorrhagic telangectasia (HHT) or Rendu-Osler-Weber syndrome, is a rare genetic disorder with autosomal dominance and variable penetrance. The typical findings of the disease are telangiectasias in skin and mucous membranes, and arteriovenous malformations presenting in the organs like lung, intestine, brain and liver. It is characterized by the classic triad of recurrent epistaxis, mucocutaneous telangiectasias and visceral hemorrhages, with familial occurrence. This article describes a case of HHT of an adult patient, associated with multiple angiodysplasic injuries in the nasal mucosa, upper gastrointestinal tract, lungs and who presents continuous blood loss, resulting iron deficiency anemia. Based on clinical and diagnostic findings, we diagnosed this case as HHT, which has rarely been reported in our literature.