Twenty-four instances of ovarian cysts detected antenatally are reported. Most cysts were functional in origin, histologically benign simple cysts. Pregnancy was clinically uncomplicated in all, followed by a spontaneous vaginal delivery in 20 cases between the 33rd and 41st week, four neonates were delivered by a cesarean section for obstetrical reasons. Nine cysts more than 5 cm in diameter at birth were treated surgically. The operative indications were as follows; 5 neonates had clinical symptoms caused by abdominal distention or vomiting. The remaining four showed a sign of hemorrhage following torsion. Thirteen cysts less than 5 cm in diameter, and two cysts more than 5 cm in diameter began to regress spontaneously within 6 months after birth and finally 10 of them disappeared between 2 weeks and 2 years.