It has been shown that intrathecal chemotherapy may cause brain damage, which can be depicted in neuroimaging studies. The aim of this work was to examine possible morphologic alterations in the brain of children with extracranial solid tumors, without CNS complications, treated with systemic chemotherapy. Brain CT images of 69 children with extracranial malignancies were reviewed and the extent of 12 CSF compartments was measured in 49 CT examinations performed during intravenously given chemotherapy and in 20 after therapy completion. Measurements were compared with corresponding normative data. About half of the children undergoing chemotherapy and half of the patients examined after treatment were found to have diffuse brain atrophy. Focal lesions that might be associated with therapy toxicity were not observed. Chemotherapy, even when administered via the systemic route, may cause brain damage, which is observed long after the end of treatment.