One hundred and twenty patients presenting with major peptic ulcer haemorrhage were randomised in a clinical trial comparing endoscopic injection and heater probe therapy. The two groups were well matched with regards to age, admission haemoglobin concentration, the presence of shock, non-steroidal anti-inflammatory drug usage and endoscopic findings. Permanent haemostasis was achieved in 87% of the injection group and 85% of the heater probe group. Hospital mortality, transfusion requirement and duration of admission were similar in both groups. Endoscopic injection and the heater probe represent equally effective therapy for peptic ulcer bleeding.