Objective. The aim of the study was to investigate the prognostic significance of p53 and mdm2 protein expressions in epithelial ovarian cancer and their relationship with the clinicopathological variables. Methods. Tumor biopsy specimens from 82 patients who were homogenously treated were examined immunohistochemically for expression of p53 and mdm2 proteins. Univariate and multivariate analyses were performed for prognostic factors, and correlations with clinicopathological parameters were examined. Results. Fifty-four percent and 33% of cases stained positive for p53 and mdm2, respectively. p53 expression was associated with serous type, higher grade, positive cytology, residual tumor and stage of the disease. rndm2 expression predicted of chemosensitivity and it was related with higher grade but not with other clinicopathological variables. Significantly poorer survival was seen for those with p53 (P < 0.05) or mdm2 (P < 0.01) positive tumors than those with negative p53 or mdm2 staining. Coexpression of p53 and mdm2 was also related to poor outcome (P < 0.05). Multivariate analysis revealed that FIGO stage, mdm2 expression, response to chemotherapy and optimal cytoreduction were significant independent prognostic and predictive factors of survival. Conclusion. Although our findings showed that mdm2 may be used as a prognostic indicator in patients with epithelial ovarian cancer, these results should be supported by more and larger studies. (c) 2005 Published by Elsevier Inc.