The identification of markers that are specifically expressed by different histological types of epithelial ovarian cancer (EOC) may lead to the development of novel and more specific diagnostic and therapeutic strategies. Sodium-dependent phosphate transporter NaPi2b (or MX35 ovarian cancer antigen) is a novel perspective marker of EOC. To date, the studies on NaPi2b/MX35 expression in different histological types of EOC are limited.To examine NaPi2b/MX35 expression in different histological types of epithelial ovarian tumors.Here, we describe the analysis of NaPi2b expression in serous (n = 17), endometrioid (n = 8), and mucinous ovarian tumors (n = 3) by Western-blotting (WB), immunohistochemistry and RT-PCR.The results of immunohistochemical and WB analysis showed that benign and well-differentiated malignant papillary serous tumors as well as well-differentiated malignant endometriod tumors overexpress NaPi2b protein. However, no overexpression of NaPi2b was detected in benign and malignant mucinous tumors as well as in poorly differentiated endometriod tumors. Notably, the expression NaPi2b mRNA was detected in all investigated histological types of EOC.We have shown the differential expression profile of NaPi2b phosphate transporter at protein level in various histological types of epithelial ovarian cancer. This finding might facilitate the development of more effective approaches for diagnosis and treatment of this disease.