The expression of nm23-H1 has been demonstrated to be highly correlated with the metastatic potential of various tumors. In the present investigation, meningiomas of different pathological grades were used to study on their nm23-H1 expression. Immunohistochemistry showed that nm23-H1 was expressed mainly in the cytoplasm especially in the perinuclear region in explants under short-term culture. Western-blotting demonstrated the specific expression of nm23 protein in all tumor samples. The expression was also found to be sex-dependent on tumor progression in female, but not in male patients. RT-PCR results confirmed nm23-H1 expression was higher in benign tumors than in their normal counterpart. Our observations thus suggest that nm23-H1 may play an important role in the progression of meningiomas in female patients.