To understand the mechanisms of telomere maintenance in human gliomas, telomerase activity, telomerase RNA expression and telomere length of surgically excised glioma samples were analyzed. Sixty-five percent of gliomas exhibited telomerase activity, the occurrence of which was not related to their histological malignancy scale. Not only the telomerase-positive gliomas, but also the telomerase-negative gliomas and normal brain expressed telomerase RNA, suggesting that the presence of telomerase RNA component does not indicate the presence of telomerase activity. Compared with telomerase-positive gliomas, telomerase-negative gliomas had long heterogeneous telomeric terminal restriction fragments. These data suggest that in addition to the telomerase-dependent mechanism, a telomerase-independent mechanism for telomere maintenance may be present in human gliomas.