Ovarian cancer is classified into three types: Epithelial (80%), Germ cell tumor (10-15%) & Stromal sex cord tumors (5-10%). Epithelial ovarian tumors are further subdivided into serous (70%), mucinous(10-15%) and endometroid (10-15%). Granulosa cell tumors represent the majority of the Stromal sex cord tumor. CA 125 is elevated in 50% of patients with stage I ovarian cancer, 90% with stage II and > 90% in stage III & IV. CA 125 is not a good tumor marker for Mucinous & Granulosa cell tumors. Inhibin B is a useful tumor marker for these two malignancies. Inhibin B elevation has been reported in 89-100% of patients with Granulosa cell tumors & 55-60% of patients with Mucinous Epithelial tumors.