Ovarian cysts are the most frequent type of abdominal tumor, in female newborns. The most of the cases resolve spontaneously with no clinical significance. However, ovarian cysts often present complications such as torsion. The authors reviewed the pre- and postnatal records and ultrasonograms of five fetuses, who were diagnosed with ovarian cysts. No complication was observed prenatally. However, one infant 2 months after birth required surgical intervention because of cyst torsion. The cysts of the other four infants showed complete resolution in a time interval of 3–9 months. An ovarian cyst is not a life-threatening condition, so they should be just closely monitored pre- and postnatally until spontaneous resolution. When torsion of the cyst is suspected, surgical intervention is necessary.