Upper gastrointestinal bleeding (UGIB) in children has many causes, with its prevalence varying by age. Often presenting as hematemesis or melena, the initial treatment is stabilization of the patient, including protection of the airway, fluid resuscitation, and a transfusion hemoglobin threshold of 7 g/L. Endoscopy should be performed with the goal of using combinations of therapies to treat a bleeding lesion, generally involving epinephrine injection along with either cautery, hemoclips, or hemospray. This review discusses the diagnosis and treatment of variceal and non-variceal gastrointestinal bleeding in children with a focus on current advances in the treatment of severe UGIB.