The paper deals with 62 ovarian cancer patients observed from 1988 to 1997. Considering the ovarian cancer stage, the patients were divided in two groups. Group I consisted of 31 patients at the early stage of ovarian carcinoma (FIGO classification I and II), while group II included 31 patients with the advanced disease (FIGO classification III and IV). According to FIGO classification, a majority of group I and group II patients was classified as IA (61.3%) and IIIC, respectively. Ovarian carcinoma of the serous pathohistologic type accounting for 48.4% prevailed in both groups, but there were also endometroid and mucinous types. Sensitivity to CA125 was observed in 93.5% of the group I and in 96.7% of the group II patients. In group I, the mean value of tumor marker CA125 read 262.97 U/ml, median 93 U/ml, ranging from 13-2000 U/ml. In comparison with group I, the mean value of group II tumor marker CA125 was significantly higher reading 1053.81 U/ml, median 365 U/ml, with CA125 levels ranging from 15-9960 U/ml. In relation to patients at the early stage of ovarian cancer, preoperative CA125 serum levels were statistically more significant in the advanced ovarian cancer patients (statistically significant difference p = 0.002). When comparing CA125 levels and tumor differentiation according to Broders, no statistically significant difference was observed in both group I (p = 0.6144) and group II (p = 0.6605). The statistically significant correlation (p = 0.00008) was confirmed between advanced ovarian carcinoma and less differentiated tumors (Broders differentiation III and IV).