Single-chain glycoprotein CD44 is a major cell surface receptor for hyaluronan and mediates epithelial cell adhesion by its involvement in cell-cell and cell-matrix interactions. Recently, CD44 has been identified as a biomarker of cancer stem cells in many malignancies including ovarian carcinoma. However, its clinical significance in human ovarian carcinoma has been controversial until recently. The aim of our current study was to clarify the clinical role of CD44 expression in human ovarian carcinoma. Immunohistochemical staining of 483 primary ovarian carcinoma and 27 paired primary and recurrent ovarian carcinoma samples for CD44 standard form (CD44s) was performed using tissue microarray. The associations between CD44s expression and clinical factors (histologic types, tumor grade, International Federation of Gynecology and Obstetrics stage, and response to chemotherapy), and overall or disease-free survivals were analyzed. We observed CD44s expression in 38% of the ovarian carcinoma samples. Results of the Fisher exact test suggested that CD44s expression was associated with high-grade carcinoma (P = .013), advanced International Federation of Gynecology and Obstetrics stage (III-IV; P < .001), age at diagnosis less than 60 years (P = .011), and transitional cell carcinoma (P = .039). However, CD44s expression was not associated with overall survival (P = .529) or disease-free survival (P = .218) by the log-rank test. Moreover, there was no statistical difference in CD44s expression between the primary and recurrent ovarian carcinomas. Our results showed that CD44s expression is not a prognostic predictor in ovarian cancer.