Purpose: The objective of this study was to evaluate the role of the expression of topoisomerase II, BCL-2, and Ki-67 in an ovarian tissue and their effects on the development and the prognosis of ovarian cancers. Materials and Methods: The study consisted of 38 female patients with ovarian cancers. Patients' characteristics, tumor type, stage, and the grade of the disease, and topoisomerase II, Bcl2, and Ki-67 values in ovarian tissue were compared. Results: Extensivenesses of topoisomerase II and Ki-67 staining in early -stage disease were found statistically different from those in the advanced stage diseases (for topoisomerase II, 60.38 33.87% vs 85 8.5%, p = 0.017, for Ki-67; 25.07 +/- 25.04% vs 51 +/- 25.29%,p = 0.012). Differences of Bcl-2 staining between two groups were not significant (30.38 +/- 38.82 % vs 18.2 +/- 30.58%, p = 0.377). Conclusions: Expressions of topoisomerase II and Ki-67 in ovarian cancer tissues were associated with advanced stage diseases and expression of Bcl-2 refers to good histological grade in patients.