Hereditary hemorrhagic telangiectasia(HHT)is a rare autosomal-dominantly inherited disease that occurs in approximately one in 5000 to 8000 people.Clinical diagnosis of HHT is made when a person presents three of the following four criteria:family history,recurrent nosebleeds,mucocutaneous telangiectasis,and arteriovenous malformations(AVM)in the brain,lung,liver and gastrointestinal(GI)tract.Although epistaxis is themost common presenting symptom,AVMs affecting the lungs,brain and GI tract provoke a more serious outcome.Heterozygous mutations in endoglin,activin receptor-like kinase 1(ACVRL1;ALK1),and SMAD4,the genes involved in the transforming growth factor-βfamily signaling cascade,cause HHT.We report here the case of a 63 year-old male patient who presented melena and GI bleeding episodes,proven to be caused by bleeding from multiple gastric angiodysplasia.Esophagogastroduodenoscopy revealed multiple angiodysplasia throughout the stomach.Endoscopic argon plasma coagulation was performed to control bleeding from a gastric angiodysplasia.The patient has been admitted several times with episodes of hemoptysis and hematochezia.One year ago,the patient was hospitalized due to right-sided weakness,which was caused by left basal ganglia hemorrhage as the part of HHT presentation.In family history,the patient’s mother and elder sister had died,due to intracranial hemorrhage,and his eldest son has been suffered from recurrent epistaxis for 20 years.A genetic study revealed a mutation in exon 3 of ALK1(c.199C>T;p.Arg67Trp)in the proband and his eldest son presenting epistaxis. Hereditary hemorrhagic telangiectasia (HHT) is a rare autosomal-dominantly inherited disease that occurs in about one in 5000 to 8000 people. Clinical diagnosis of HHT is made when a person presents three of the following four criteria: family history, recurrent nosebleeds, mucocutaneous telangiectasis , and arteriovenous malformations (AVM) in the brain, lung, liver and gastrointestinal (GI) tract. Although epistaxis is theseost common presenting symptoms, AVMs affecting the lungs, brain and GI tract provoke a more serious outcome. Heterozygous mutations in endoglin, activin receptor-like kinase 1 (ACVRL1; ALK1), and SMAD4, the genes involved in the transforming growth factor-β family signaling cascade, cause HHT. We report here the case of a 63 year-old male patient presented presented with melena and GI bleeding episodes , proven to be caused by bleeding from multiple gastric angiodysplasia. Esophagogastroduodenoscopy revealed multiple angiodysplasia throughout the stomach. Endoscopic argon plasma coagulation was pe rformed to control bleeding from a gastric angiodysplasia.The patient has been admitted several times with episodes of hemoptysis and hematochezia. One year ago, the patient was hospitalized due to right-sided weakness, which was caused by left basal ganglia hemorrhage as the part of HHT presentation.In family history, the patient’s mother and elder sister had died, due to intracranial hemorrhage, and his eldest son has been recovered from recurrent epistaxis for 20 years. A genetic study revealed a mutation in exon 3 of ALK1 (c.199C > T; p.Arg67Trp) in the proband and his eldest son presenting epistaxis.