BACKGROUND Upper gastrointestinal (GI) bleeding is defined as bleeding proximal to ligament of Treitz. Its clinical presentations are hematemesis, melena stool, or even fresh bleeding per rectum. This paper reviews the diagnosis and treatment of upper GI bleeding. METHODS Selective literature review. RESULTS Common causes of upper GI bleeding are peptic ulcer disease, bleeding from gastroesophageal varices, angiodysplasias, and Mallory-Weiss lesions. The most important diagnostic intervention is endoscopy, which allows therapeutic interventions if needed. Peptic ulcer disease is treated endoscopically with injection therapy and endoclips. Acute bleeding from oesophageal varices is treated by banding. Endoscopic treatment is accompanied by medical treatment with proton pump inhibitors for the treatment of peptic ulcer disease, and vasoactive drugs for the treatment of bleeding oesophageal varices. CONCLUSIONS Modern endoscopy affords good localization of the bleeding site and successful treatment for most patients with upper GI bleeding.