Peutz-Jeghers syndrome is an autosomal dominant inherited disorder characterized by hamartomatous polyps in the small bowel and mucocutaneous pigmentation. Patients with Peutz-Jeghers syndrome often present as surgical emergencies with complications of the polyps, such as intussusception, bowel obstruction and bleeding. Furthermore, repeated operations may be needed in some patients, which may result in short bowel syndrome. Although early reports did not demonstrate a predisposition to cancer in patients with this syndrome, more recent studies have described an increased risk for both gastrointestinal and extra-gastrointestinal cancers. Women with the Peutz-Jeghers syndrome have the extremely high risk for breast and gynecologic cancer. Recently, Peutz-Jeghers syndrome susceptibility gene, encoding the serine threonine kinase STK11 (also called LKB1), was identified in families with Peutz-Jeghers syndrome. The identifications of germline mutations in families with Peutz-Jeghers syndrome could be a turning point in the management of Peutz-Jeghers syndrome.