The juvenile granulosa cell tumors of the ovary tumors belong to the group of stroma and sex cord tumors. These are rare tumors representing 1 - 2% of ovarian tumors. These tumors are involved in ovarian hormone function, responsible for the synthesis of hormones (estrogen, corticosteroids), which explains the hormonal dysfunctions associated with these cancers. The juvenile granulosa cell tumors occur in older children, usually before the age of 20 years old, with a maximum frequency in pre puberty. We report an exceptional case of a granulosa tumor in a four- month infant