Introduction: Gastrointestinal (GI) bleeding remains a common clinical problem encountered by every emergency room and trauma physician. Endoscopy remains the main approach to the diagnosis and therapy of GI bleeding. Objectives: To present the modern endoscopic approach for GI bleeding. Methods: Narrative review based on our expertise and inclusion of classic articles dealing with interventional and therapeutic GI endoscopy. Results: GI hemorrhage is now classified as upper, middle, and lower GI bleeding. Upper GI bleeding is defined as hemorrhage originating from the oropharynx to the ligament of Treitz (or papilla of Vater), middle GI bleeding occurs distal to the papilla of Vater to the terminal ileum, and lower GI bleeding is defined as bleeding distal to the ileocecal valve, including the entire colon and anorectum. Endoscopic methods used to diagnosed and treat GI bleeding include esophagogastroduodenoscopy, duodenoscopy, capsule endoscopy, double- and single-balloon enteroscopy, spiral enteroscopy, and colonosocopy. Conclusions: This is the first review paper dedicated to endoscopic therapy for bleeding involving any part of the luminal GI tract (i.e., esophagus, stomach, small bowel, and colon). Modern endoscopy permits the investigation and treatment of the majority of conditions affecting the entire hollow GI tract. © 2011 Springer-Verlag.