With good medical management of the peptic ulcer he incidence of perforated duodenal ulcer and the hospitalization rate for treatment have decreased. However, the rate of complicated perforated duodenal ulcer appears to be unchanged. In most cases of perforation, gastric and duodenal content leaks into the peritoneum. This content includes gastric and duodenal secretions, bile, ingested food, and swallowed bacteria. The leakage results in peritonitis, with an increased risk of infection and abscess formation. Subsequent third-spacing of fluid in the peritoneal cavity due to perforation and peritonitis leads to inadequate circulatory volume, hypotension, and decreased urine output. In more severe cases, shock may develop. Abdominal distension as a result of peritonitis and subsequent ileus may interfere with diaphragmatic movement, impairing expansion of the lung bases. Eventually, atelectasis develops, which may compromise oxygenation of the blood, particularly in patients with coexisting lung disease. Several surgical techniques have been employed in the treatment of perforated peptic ulcer. These include conservative surgery with patching of the ulcer, peritoneal lavage, and antiulcer medication, and definitive surgery with truncal vagotomy, highly selective vagotomy, or partial gastrectomy. Some studies have reported a high rate of ulcer recurrence in the conservative surgery group and have recommended definitive ulcer surgery for perforation.