Surgical treatment of acute perforated gastric and duodenal ulcer is connected to high postoperative lethality. By emergency procedure it has to be decided between performing a simple closure or performing initially a definitive operation to control the peptic disease. The therapeutic options at our institution are based on a severity score which includes patient's age, associated pathology, grade of the peritonitis, delay between the onset of symptom and surgery, history of ulcer disease. Charts of 90 patients consecutively operated during 6 years for acute perforated ulcer were analysed. The average age was 65.5 years, the operation was performed within 6 h in 47.3% of the patients. To perform or not a definitive operation is an important therapeutic option as by simple closure 45% recurrence is observed with a lethality of 36%. Based on our scoring system, 87.9% of all the patients underwent definitive operation. The lethality rate of this series of nonselected patients (52% were older than 70 years) was low: 6.3%. The use of the severity score help to choose patients to be treated by simple closure and patients which may be submitted to definitive emergency operation with low operative risk.