Gastric angiodysplasia is a very rare cause of upper gastrointestinal bleeding in children and adolescents and is considered to be a vascular abnormality with a developmental cause. Gastric angiodysplasia can be managed with various endoscopic methods, including argon plasma coagulation, electrocoagulation, heater probe, sclerotherapy, band ligation, and hemoclipping therapy. We describe a case of gastric angiodysplasia in a 12-year-old boy with hematemesis and melena. Gastroduodenoscopy showed a typical lesion of angiodysplasia with oozing on the posterior wall of the gastric body. We successfully performed endoscopic hemoclipping therapy to heal the bleeding lesion, and no recurrence of bleeding was observed on follow-up. Gastric angiodysplasia should be included in the differential diagnosis of upper gastrointestinal bleeding in children.