Many claim that upper gastrointestinal hemorrhage in patients with varices is frequently not of variceal origin. Such teaching is contrary to our experience. We therefore reviewed the records of 127 consecutive patients with 165 episodes of acute upper gastrointestinal bleeding who were found to have esophageal varices by endoscopy. Varices were the only potential site of the index bleed in 101 of the 127 patients (79.5%). In addition to varices, other potential sites of bleeding were gastric ulcer in 9 (7%), Mallory-Weiss tear in 4 (3.1%), duodenal ulcer in 3 (2.3%), and multiple gastroduodenal erosions in 10 (7.8%). We used the characteristics of the clinical presentation (e.g., varix seen bleeding) and the known natural course of the variceal bleeding to attempt to define the site of bleeding in the group with more than one potential site. In 15 we could make a judgment as to the likely source: In 9 it was variceal and in 6 nonvariceal. When varices are seen at endoscopy in a patient with a major hemorrhage, they are responsible for the bleeding in greater than 80% of cases.