In childhood and adolescence, pituitary adenomas are rare and half are prolactinomas. However, cystic giant prolactinoma in prepuberty is extremely rare. In this report, we present a 10-year-old boy with a cystic giant prolactinoma who was treated with two-stage surgery as the tumor was dumbbell shaped. To our knowledge, this is the second reported case of a cystic giant prolactinoma in a prepubertal child.