The morbidity and mortality rate of ovarian cancer patients are significantly inclined recently in Japan. FIGO stage is a powerful prognostic factor, hence treatment schedule must be based on precise staging. For stage I patients, total abdominal hysterectomy (TAH), bilateral salpingo-oophorectomy (BSO), partial omentectomy (p-OMTX) and appendectomy (APX) are included to standard surgical procedure. Adjuvant chemotherapy consisted with CAP (cyclophosphamide, adriamycin, cisplatin) or CP is given for 5 courses postoperatively. However, those who are stage Ia (grade 1) and desire child bearing could have unilateral salpingo-oophorectomy and conserve conceptability. Adjuvant chemotherapy for those patients is now on prospective randomized trial in Japan. One arm is 50 mg/day of cyclophosphamide for 3 months and the other arm is cyclophosphamide 500 mg/m2 + CDDP 75 mg/m2 every 4 weeks for 3 courses. For stage II or more patients, total omentectomy and retroperitoneal lymphadenectomy are added to above mentioned procedure. Cisplatin (15.75 mg/m2/week or more) based adjuvant chemotherapy is given for 5-10 courses. Therapeutic significance of retroperitoneal lymphadenectomy is also under study in patients who are optimally debulked (< 2 cm residual tumor). They are randomly divided into two groups: lymphadenectomy group and no-lymphadenectomy group. They receive 5 courses of CP therapy (cyclophosphamide 600 mg/m2 + CDDP 75 mg/m2) afterwards. Survival rate and time to progression are the primary endpoints.