The visible vessel in the floor of the ulcer seen on endoscopy is one of the most important prognostic factors of ulcer bleeding. With the ultimate aim of improving the purely visual interpretation of the base of the ulcer, we investigated the utility of an innovative pulsed endoscopic Doppler procedure in 140 patients with acute ulcer bleeding. Agreement between the endoscopic appearance and the Doppler ultrasonographic findings was observed in only 59% of the ulcers. In all Doppler-positive ulcers, injection therapy was performed irrespective of the endoscopic appearance of the ulcer. This was repeated if the ulcer was still Doppler-positive on repeat examination. With this strategy, only 9% recurrent hemorrhages were seen, and there was no hemorrhage-associated mortality. Among the Doppler-negative lesions, which received only medical treatment, no rebleeding was observed. On the basis of these results, it would appear that a Doppler ultrasound oriented classification of ulcer bleeding is superior to the Forrest classification based on a purely visual interpretation. The endoscopic Doppler verifies the visual impression of the ulcer, identifies the indication for operative endoscopy, and can monitor the effectiveness of the latter.