Gastrointestinal duplications are unusual congenital malformations, nearly always diagnosed in childhood. Roughly 80% are cysts-like lesions and only a small percentage (4-18%) involves the colonic wall. Almost all are asymptomatic and therefore diagnosed as an incidental finding on imaging tests or when become complicated and present with perforation or bleeding. The need for an elective surgical treatment is controversial and should be indicated on an individual basis. This report is a case of an adult with a complete tubular colonic duplication found incidentally by colonoscopy that required surgical treatment due to perforation.