In parts I and II of this article, we touched on some of the newer innovative therapeutic approaches that are presently being evaluated in brain tumors in children, such as monoclonal antibody-directed therapy of brain tumors, implantation irradiation techniques, and related techniques. Nevertheless, the potential uses of the many conventional chemotherapeutic agents now available in our treatment of brain tumors in children are far from exhausted. In some senses, pediatric neuro-oncologists have achieved the same level of sophistication, and similar outcome, that our pediatric oncologists achieved 25 years ago in the treatment of Wilms' tumor. By 1960, children with Wilms' tumor were achieving 50% cure rates following early attempts at incorporating chemotherapy into the therapeutic armamentarium. Did researchers anticipate that their coordinated efforts, through multicenter cooperative group trials, would lead to more than 80% cure rates in the 1980s? Of course, there is no preordained guarantee that children with brain tumors will achieve the same therapeutic successes that children with Wilms' tumor have achieved. Nevertheless, our modest successes with chemotherapy over the past 10 years should offer encouragement to our colleagues as well as to our patients. These successes may finally dispel the pessimism and trepidation with which too many physicians have approached the problem of the child with a brain tumor for so long.