Abstract Background Ovarian serous cystadenomas are rare in children. No case of recurrence after surgical resection in a premenarchal girl has been published. Case An 8-year-old presented with abdominal pain and ultrasound showed bilateral ovarian cystic masses with normal clinical and laboratory exam. Cystectomies were performed revealing serous cystadenomas. Ten months later, her pain returned and ultrasound showed new cysts. Persistence of cysts and symptoms required repeat surgery with the same pathology. Summary and conclusion Premenarchal girls with ovarian cystic masses require surgical intervention in cases of persistent symptoms, uncertain diagnosis, or concern for ovarian torsion. With reassuring imaging and tumor markers, conservation of the ovary can be achieved with cystectomy alone. Ultrasound follow-up is recommended after surgical resection until bimanual exam can be performed.