The umbilicus is remaining scar tissue from the umbilical cord in the fetus. If the omphalomesenteric duct in theumbilicus is not properly closed, an ileal-umbilical fistula, sinus formation, cysts, or, most commonly, Meckel’s diverticulum can develop. The others are very rare and mostly occur in the pediatric population. We describe hereina 61-year-old female with a giant omphalomesenteric cyst presented as an asymptomatic infraumbilical mass. Toour knowledge, this is the oldest patient reported and the largest cyst described in the literature. The diagnosis ofa painless abdominal mass frequently suggests malignancy in older patients. But, extremely rare conditions can bedetected, such as an omphalomesenteric cyst.