Familial Adenomatous polyposis (FAP) it is based on an autosomal dominant mutation which results in loss of function of theAPC tumor suppressor gene. On the other hand, Gardner syndrome is a type of FAP and is characterized for multiple colonic adenomatous polyps and extracolonic abnormalities as desmoid tumors, osteomas, lipomas, dental abnormalities, dermoid cysts and duodenal adenomas. This report aims to present two patients with FAP: The first one is a patient who presented with osteomas and hematochezia, being diagnosed with Gardner Syndrome after the colonoscopy. The second patient has a family history of colon cancer, who is diagnosed with FAP with tubular adenocarcinoma. We decide to report both cases due to the absence of previous reports in Peru.