Duplication cysts are congenital malformations of the gastrointestinal tract. They are rare, occurring in 1 in 4,500 births.1 Although the age of symptomatic onset is typically 2 years, current literature shows reports of presentation from newborn to adulthood. Presentation of duplication cysts may vary widely and can occur during outbreaks of acute infectious gastroenteritis cases. Thus, it is important to consider these cysts in the differential diagnosis of the vomiting child. We report the case of a 7-year-old boy with persistent bilious vomiting who was found to have a bilobed duplication cyst. [Pediatr Ann. 2023;52(7):e273-e276.].