Aims. To investigate whether there is a correlation between serum tumor markers panel ( CA 125, CA 19-9, CA 15-3, and carcinoembryonic antigen (CEA)) and tumor size and histopathology in well staged patients with borderline ovarian tumors (BOTs). Methods. Four tumor markers ( CA 125, CA 19-9, CA 15-3, and CEA) were analysed clinically in 60 well staged patients with borderline ovarian tumor, for this retrospective observational study. Results. Most patients had serous histology and early stage disease, and the mean age at the time of diagnosis was 40.70 years ( range: 19 - 73). Twenty-nine patients (48.3%) had high CA 125 levels ( > 35 U/l), 15 patients (25%) had high levels of CEA ( > 4 ng/ml), 12 patients (20%) had high levels of CA 19-9 ( > 37 U/ml), and 9 patients (15%) had high levels of CA 15-3 ( > 30 ng/ml) at the time of initial surgery. The positive rate of CA 125, CA 19-9, CA 15-3, and CEA in serous tumor were 57.9, 7.9, 7.9 and 15.8%, respectively. These figures were 31.8, 40.9, 27.3 and 40.9% in mucinous tumor. The positive rate of CA 125 in the serous group was statistically significantly higher than that in the mucinous group, while the positive rates for CA 19-9 and CEA in mucinous histology was significantly higher than those in serous tumors. In case of grouping the tumor size as < 4, 4.1-10 and > 10 cm, the mean serum levels of tumor markers had significantly increased by increasing tumor size ( p < 0.05 for CA 125, and CA 19-9, p > 0.05 for CA 15-3, and CEA). Conclusion. The high levels of tumor markers, especially for CA 125 and CA 19-9, may indicate the larger tumor size. The elevation of serum CA 125 may suggest serous tumors, while the high level of serum CA 19-9 and CEA may indicate mucinous BOTs.