Cell division cycle 25 (CDC25) phosphatases are cell-cycle regulatory proteins which are overexpressed in a significant number of human cancers. This study evaluated the role of CDC25 phosphatases in human glioma proliferation. Upregulation of CDC25A was observed in human glioma specimens and human glioma cell lines. Comparison of expression levels of CDC25A and CDC25B messenger ribonucleic acid (RNA) to Ki-67 labeling index in glioma tissues found that Ki-67 labeling index was significantly correlated with the expression of CDC25A, but not with that of CDC25B. Depletion of CDC25A by small interfering RNA and inhibition of CDC25 suppressed cell proliferation and induced apoptosis in glioma cell lines, indicating that CDC25A is a potential target for the development of new therapy for glioma.