A new technique of treating acute severe upper gastrointestinal haemorrhage was evaluated. The technique consisted of epinephrine injections in the bleeding lesion combined with YAG laser radiation in short pulses, applied until the bleeding vessel was completely closed. This new treatment modality was tried in 54 consecutive patients with severe upper gastrointestinal bleeding from a spurting artery, or an ulcer with a non-bleeding visible vessel in the floor of the ulcer crater at endoscopy. Permanent haemostasis was achieved in 87% of the 54 patients. Emergency surgery was needed in 13%. The mortality rate was only 10%. No complications occurred. It is concluded that this new technique of treating severe upper gastrointestinal bleeding from a spurting artery, or an ulcer with a visible vessel results in a significant improvement of the success rate (permanent haemostasis) and a marked reduction in the mortality rate.