Intratumoral steroidogenesis is considered to play important roles in the biologic behavior of common epithelial ovarian carcinoma. Recent studies have demonstrated the important roles of Ad4BP/SF-1 and DAX-1 in regulation of steroidogenesis. In this study, we evaluated DAX-1, Ad4BP/SF-1, StAR, and steroidogenic enzyme expressions and their correlations in epithelial ovarian carcinomas to evaluate the possible roles of these factors in regulation of intratumoral steroid metabolism and/or production. Immunolocalization of DAX-1, Ad4BP/SF-1, StAR, and steroidogenic enzymes were examined in 90 epithelial ovarian carcinomas. mRNA expression of these proteins was evaluated using real-time polymerase chain reaction (PCR) in 23 cases for further characterization. DAX-1 and Ad4BP/SF-1 immunoreactivity was detected predominately in the nuclei of tumor cells, whereas that of StAR and steroidogenic enzymes was present in the cytoplasm. We detected a significant positive correlation between StAR and steroidogenic enzymes immunoreactivity and Ad4BP/SF-1 and statistically inversed correlation with DAX-1. A positive statistical correlation was detected between intratumoral stromal Ad4BP/SF-1 immunoreactivity and clinicopathologic parameters of carcinoma patients. Results of real-time PCR analysis were correlated with those of immunohistochemical studies. The status of intratumoral DAX-1, Ad4BP/SF-1, and StAR and steroidogenic enzymes in epithelial cells and intratumoral stromal cells of epithelial ovarian carcinoma may contribute in the progression and/or aggressiveness of these tumors.