BACKGROUND/AIM: The aim of this study was to clarify the biological differences between ovarian cancer-associated fibroblasts (OCa-CAFs) and normal ovary-derived mesenchymal stem cells (NO-MSCs). MATERIALS AND METHODS: Surgically resected ovarian cancer and contralateral normal ovarian tissue samples were cut into small pieces for culture as "explants". The number of outgrown cells, their proliferative kinetics, and expression levels of cell surface markers of CAFs, as well as three miRNAs in OCa-CAFs and NO-MSCs were compared directly. Differentially expressed genes between both groups were also investigated. RESULTS: Comparable numbers of outgrown cells were harvested from both groups. Significantly higher expression of α-smooth muscle actin and miR-142 was found in OCa-CAFs, which decreased significantly during ex vivo cell expansion. A total of 21 differentially expressed genes were identified between both groups. CONCLUSION: OCa-CAFs showed different biological properties in direct comparison with NO-MSCs, which might play major roles in the pathogenesis of ovarian cancer.