Endoscopic hemostatic therapy for upper gastrointestinal bleeding is gaining widespread acceptance despite often conflicting results of randomized controlled trials. To examine the effect of endoscopic therapy in acute nonvariceal upper gastrointestinal hemorrhage, a meta-analysis was performed using a computerized search of the English-language literature and a bibliographic review. The methodology, population, intervention, and outcomes of each relevant trial were evaluated by duplicate independent review. Thirty randomized controlled trials evaluating hemostatic endoscopic treatment were identified. Endoscopic therapy significantly reduced rates of further bleeding (odds ratio, 0.38; 95% confidence interval, 0.32-0.45), surgery (odds ratio, 0.36; 95% confidence interval, 0.28-0.45), and mortality (odds ratio, 0.55; 95% confidence interval, 0.40-0.76). When analyzed separately, thermal-contact devices (monopolar and bipolar electrocoagulation and heater probe), laser treatment, and injection therapy all significantly decreased further bleeding and surgery rates. The reductions in mortality were comparable for all three forms of therapy, but the decrease reached statistical significance only for laser therapy. Further examination of subgroups indicated that endoscopic treatment decreased rates of further bleeding, surgery, and mortality in patients with high-risk endoscopic features of active bleeding or nonbleeding visible vessels. Rebleeding was not reduced by endoscopic therapy in patients with ulcers containing flat pigmented spots or adherent clots. Endoscopic hemostatic therapy provides a clinically important reduction in morbidity and mortality in patients with acute nonvariceal upper gastrointestinal hemorrhage.