The need for emergency endoscopy is a matter of debate. The time interval for emergency procedures remains to be defined. Most authors propose a time span of 24 h as emergency time, while some define a period of 72 h (especially in acute pancreatitis). Several studies have shown a possible benefit for a select group of patients. Four main indications are established for emergency endoscopy: acute gastrointestinal bleeding (variceal and nonvariceal), acute biliary pancreatitis and acute cholangitis. In the case of upper gastrointestinal bleeding, emergency endoscopy enables exact diagnosis and appropiate therapy, and provides important prognostic information. There is some evidence that emergent endoscopic injection therapy improves clinical outcome and reduces mortality in patients with acute ulcer bleeding. Patients do not benefit if endoscopy is performed only as a diagnostic procedure. Controversial results were published recently for emergency endoscopy in acute biliary pancreatitis. There is good evidence that emergency endoscopic retrograde cholangiopancreatography is helpful in patients with severe pancreatitis and stone impaction if performed within the first 24 h after onset of symptoms. However, emergency endoscopic retrograde cholangiopancreatography is not benefical for patients with mild pancreatitis if performed later than 72 h (or 24 h) after onset of symptoms. There is a limited number of well established evidence-based indications for emergency endoscopy. Some other indications are still a matter of debate, and controversial opinions have been published.