Survival of children with brain tumors has improved over the past 20 years due in part to advances in surgery, radiation, and most recently chemotherapy. The long-term adverse effects of radiation and chemotherapy on these children is the subject of this report. In Part I, we reviewed the pathologic consequences of radiation, including leukoencephalopathy, radiation necrosis, and radiation myelopathy as well as the oncogenic effects of both radiation and chemotherapy. Part II addresses the long-term consequences of radiation and chemotherapy on intellectual and endocrine function. Risk factors for the development of both endocrinopathies and intellectual dysfunction include age at the time of radiation, volume and dose of radiation, site of tumor, and use of adjuvant chemotherapy, in particular methotrexate. Early recognition of these complications and treatment, where indicated, will measurably improve the quality-of-life of children treated for brain tumors. The national cancer groups are currently attempting to limit these long-term adverse effects by taking risk factors into account when formulating new treatment regimens.