This study aimed to evaluate the relationship of LMX1A and osteopontin (OPN) expression with clinicopathologic parameters for the 4 most common ovarian surface epithelial carcinomas. Both biomarkers were investigated immunohistochemically using tissue microarrays of 249 specimens including 91 serous cystadenocarcinomas, 56 mucinous cystadenocarcinomas, 64 endometrioid adenocarcinomas, 26 clear cell carcinomas, and 12 normal ovarian tissues. All 4 carcinomas showed significant expression of LMX1A and OPN. In addition, higher immunostaining scores and percentage of cells stained for LMX1A in mucinous cystadenocarcinomas correlated with T stage, American Joint Committee on Cancer clinical stage, poorer tumor differentiation, and poorer survival rate. In serous cystadenocarcinoma, higher percentage of staining for OPN and higher intensity or immunostaining scores for LMX1A correlated with poorer tumor differentiation. Thus, the expression of LMX1A may be an independent prognostic risk factor in mucinous cystadenocarcinoma and a helpful marker in evaluating this tumor's aggressiveness.