Intestinal duplication is a rare congenital malformation that can occur in any segment of the digestive tract. It is most commonly found in the ileum of infants and is rarely reported in adults, especially in the colon. Diagnosing intestinal duplication can be extremely challenging due to its diverse clinical manifestations and complex anatomical structure. Surgical intervention is currently considered the mainstay of treatment. In this report, we presented a case of giant duplication of the transverse colon in an adult.