Ovarian size progressively increases in infancy, from 2cm to more than 3cm in length during the hormonal stimulation which occurs during the pubertal stage. The presence of ovarian follicules is a normal finding whatever the age; the presence of multifollicular ovaries is common during the pubertal stage. In the neonatal stage, marked by the maternal hormone influences, a cystic mass must be considered as an ovarian cyst whatever the location, abdominal or pelvic. Hemorrhagic ovarian cysts with a solid and heterogeneous pattern are frequent. In the pre and peripubertal stages, it is important to recognize functional ovarian cysts, which are common, fluid filled, variable in size from 3 up to 8cm. No treatment is generally required and a number of these cysts spontaneously resolve. Organic cysts of the ovary are rare in adolescence and infancy. The most frequent germ cell tumor is the cystic dermoid or mature teratoma. In the menopausal stage, the questions arise differently: complex cysts (thick wall, septae, heterogeneous structure) require surgical advice; simple cysts, both fluid filled and unilocular, require follow up if less than 3cm, a puncture from 3 to 5cm, and a surgical procedure when greater than 5cm.