The Peutz-Jeghers syndrome is an autosomal dominant disorder characterized by the presence of hamartomatous polyps and characteristic mucocutaneous pigmentations. It is a rare syndrome and its associated to high risk for both gastrointestinal and non-gastrointestinal malignancies. The case of a patient, 32 years old, with symptoms of abdominal pain and rectal bleeding is reported. The upper gastric endoscopy and colonoscopy showed hamartomatous polyps and a tumor in the colon. Reported as a tubular polyp with severe dysplasia, the patient underwent surgical treatment. The final anatomopathologic diagnosis was colon adenocarcinoma.