In children with primary extracranial neuroblastoma (NB), intrinsic central nervous system (CNS) metastases (brain parenchyma or leptomeninges) are thought to occur rarely. This study was done to evaluate our anecdotal experience, which suggested that CNS involvement is becoming more frequent. Reports of computed tomographic (CT) and magnetic resonance (MR) imaging scans, biopsies, cerebrospinal fluid (CSF) cytologies, and autopsies were reviewed for children with stage IV NB diagnosed in 1978-1993 and followed at the Children's Hospital of Pittsburgh. Of 43 children over the age of 1 year, CNS metastases were documented in 7 (16.2%). Six patients developed signs or symptoms best explained by the presence of CNS tumor and had radiographic and/or histologic evidence of parenchymal disease (cortical masses on CT and MR, n = 3; suprasellar mass on CT, n = 1; diffuse leptomeningeal carcinomatosis by MR and/or autopsy, n = 2). CSF cytologies were positive in the one patient so tested. An additional asymptomatic patient had extensive CNS involvement at autopsy. In two of these children, the CNS was the first or only site of recurrent disease. It is concluded that intrinsic CNS disease is not uncommon in children with NB over the age of 1 year and there has been a trend toward its increasing recognition in recent years. Whether this is a function of wider use of diagnostic tools or a true change in natural history over time with increased intensity of chemotherapy is not clear. A study that prospectively monitors children with advanced neuroblastoma, radiographically and with CSF cytologies (prior to treatment and at 6-monthly intervals), is under way and should help to better define the natural history in the context of current therapies.