Recent years have seen rapid progress in our understanding of the molecular basis of brain tumors, particularly malignant astrocytomas. Translation of these advances from basic molecular genetics into the clinical arena is now underway. Molecular markers that correlate with prognosis in individual patients are being sought, and work is beginning on the identification of individuals who are at increased risk for developing a malignant brain tumor. Goals for the future include the development of more effective treatment strategies based on a clearer understanding of the pathogenesis of these tumors.