We treated 35 patients in shock from massive peptic ulcer hemorrhage with the heater probe (HP). Twelve of them (34.3%) were poor surgical candidates. Their mean age was 62.3 years. All had massive bleeding, requiring an average of 2,300 ml of blood transfusion. The average lowest mean hemoglobin was 7.94 g/dl. We used the Olympus GIF-1T10 and the HP unit, applying an average of 899 J to each bleeder. In 34 patients (97.1%) hemostasis was achieved after initial treatment. Six patients (17.6%) rebled within 1 week. With HP therapy in those six we achieved hemostasis in five (83.3%). Ultimately, only two cases failed in this study, to give a success rate of 94.3% (33/35). We conclude that HP thermocoagulation may, in the near future, replace operations in many patients with massive peptic ulcer hemorrhage.