The Peutz-Jeghers syndrome is an autosornal dominant condition characterized by mucocutaneous pigmentation and hamartomatous polyps of the gastrointestinal tract. This syndrome is clinically important because of complications caused by gastrointestinal polyps, such as abdorninal pain, gastrointestinal bleeding and intussusception often leading to intestinal obstruction. The possibility of malignant change in the polyp has been a controversial issue. In the recent reviews of soe cases of Peutz-Jeghers syndrome, the reported lesions of small intestinal adenocarcinoma are regarded as the benign process of enteritis cystica profunda. We present herein a case of Peutz-Jeghers syndrome with small bowel perforation, a previously unreported instance, and enteritis cystica profunda. (Korean J Gastroenterol 1997; 29:677-682)