Most adult primary brain tumors are gliomas. These tumors are progressive, tend to recur after treatment, and are usually fatal. Some studies on the behavior of astrocytomas with similar histological features have looked at over expression of p53 and c-erbB-2 and the immunoreactivity associated with this, at proliferative indices such as PCNA, and at AgNOR count. In this study, we identified a positive relationship between tumor progression and p53 and c-erbB-2 immunoreactivity. PCNA staining and AgNOR counts were higher in cases of tumor recurrence.