Fetal ovarian cyst was diagnosed by antenatal ultrasonic examination in eight pregnancies. In one case the cyst was antenatally twisted and necrotic, and the pregnancy resulted in premature birth during the 34th week. The other cases had clinically normal antenatal courses. One cyst ruptured at birth. The clinical condition of this and all the other neonates was good. Three of the neonates were managed surgically and five by conservative follow-up with repeated ultrasonic examinations. Cystic tumors of these infants disappeared without clinical complications in the subsequent six months. An ovarian etiology for cystic pelvic tumor of a female fetus should be considered. Conservative treatment after birth is possible in many cases with spontaneous involution likely during the first months of life.