Granulosa cell tumors (GCT) are rare tumors of the ovary, arising from sex cord stromal cells and account for 3-5% of all ovarian tumors. These tumors were first described by Rokitansky. There are 2 types- adult variety and juvenile variety. Adult GCTs are 95% of total GCTs and are most commonly found in age group of 50-55 years. Juvenile GCTs are rare tumors occurring in young girls usually before menarche and account for 5% of all GCTs. These are functional tumors which secrete estradiol which leads to various manifestations like isosexual precocious pseudopuberty in juvenile type and abnormal vaginal bleeding (menometrorrhagia) in perimenopausal & postmenopausal women in adult types. Due to prolonged hyperestrogenic state, there is evidence of endometrial hyperplasia leading to well differentiated endometrial carcinoma in 5 % of patients. We are reporting case of an 80 years postmenopausal female with moderately differentiated endometrioid adenocarcinoma endometrium with less than 50% myometrial invasion with stage 1A granulosa cell tumor of left ovary in final histopathology post surgery. These tumors have different biology and clinical presentation than that of epithelial ovarian cancers that are stage III at diagnosis in most of the cases. Most of GCTs are stage I at diagnosis (80-90%). There is delayed recurrence potential in these tumors. There are 4 times increased risk of developing breast cancer as well as due to hyperestrogenic state. There are very few cases of synchronous GCT and endometrial carcinoma in literature and with best of our knowledge, no such case has been reported from India.