From 1987 till 1997 110 patients with stage-I ovarian malignant tumors were treated and follow-up at the Department of Gynaecological Oncology, National Oncological Center. Papillifery-adenocarcinoma were in 40 cases, serous carcinoma were in 26 cases, mucinous carcinoma were in 15 cases, malignant granulosa cell tumor were in 14 cases, endometrioid carcinoma were in 6 cases, dysgerminoma were in 6 cases, Teilum's tumour were in 2 cases, and 1 case of ovary sarcoma were detected. Radical operated on the first operation were 69 patients (62.8%), and in 37 cases (33.6%) second operation for radicality were performed. In 4 cases only adnexectomy were done. In all cases post operative adjuvant chemotherapy were used. The patients were follow-up by tumour markers, sonography and CT. Follow-up period is from 5 months till 11 years. Alive were 80 patients (73%), and 30 patients (27%) were died. The patients with stage Ic and those nonradical operated in the first operation have worst prognosis then patients with stage Ia and stage Ib. The patients with ovarian tumours must be operated only in the hospitals with possibility of urgent hystological diagnosis for better prognosis in the cases of stage-I malignant ovarian tumours.