Twenty-one borderline ovarian tumour cases, diagnosed and treated in our oncology section between 1986 and 1996, were retrospectively analysed. Thirty-three percent of the cases had serous tumours and the rest (66.6%) were mucinous, 57.1% of the mucinous tumours were the intestinal type and the remaining 42.9% were the endocervical type. When all the cases were analysed, the average age was 45.4+/-18.6 years, the average follow-up period was 5.5+/-2.6 years. The preoperative average CA125 level was 55.1+/-51.9 U/mL, and for CA19.9 it was 48.2+/-47.8 U/mL. Of the patients 85.7% were stage I and 14.3% state III. There were not any significant differences between the serous, intestinal-type mucinous and endometroid-type mucinous tumours regarding tumour volumes (p>0.05). When serous and mucinous rumours were compared according to the tumour markers, CA125 levels were significantly higher in the serous tumours (p=0.04) and CA19.9 levels were significantly higher in the mucinous rumours (p=0.02). All of the patients are under our follow-up and are in remission, except one, who died in the third year of the treatment because of chronic renal failure unrelated to the ovarian pathology.