The ability to diagnose, monitor, and treat CNS tumors has been improved by new imaging techniques such as positron emission tomography (PET) scanning and functional MR imaging, stereotactic surgery, delivery of radiotherapy with brachytherapy and radiosurgery, and novel methods for delivering chemotherapy. These innovations combined with the new information about tumor pathogenesis and behavior revealed by molecular research give hope that more specific treatments for malignant CNS tumors will be developed in the future.