Foetal and neonatal ovarian cysts have previously been considered uncommon. With the development of sonography, however, the detection of cysts has increased. As ovarian cyst formation in the perinatal period is a self‐limiting process, treatment options depend on the risk of complications and on the ability to differentiate these benign cysts from other pathology. The history of two neonates with an ovarian cyst detected antenatally with ultrasound techniques is described. Conclusion: It is important that paediatricians have knowledge about the incidence, treatment and prognosis of foetal neonatal ovarian cysts.