OBJECTIVE To determine the incidence and prognosis of children who develop brain metastasis. METHODS The medical and tumor registry records of 611 children treated at the University of Iowa Hospitals and Clinics between 1965 and 2000 for a sarcoma, neuroblastoma, or Wilms' tumor were reviewed. RESULTS Thirty children (4.9%) were found to have brain metastasis. Brain metastasis occurred in 9 of 113 (8%) neuroblastoma, 7 of 104 (6.7%) rhabdomyosarcoma, 6 of 105 (5.7%) Ewing's sarcoma, 5 of 106 (4.7%) osteosarcoma, 2 of 83 (2.4%) nonrhabdomyosarcoma soft-tissue sarcoma, and 1 of 100 (1%) Wilms' tumor patients. There were 22 male and 8 female patients, with a median age of 14 years at the time of diagnosis of brain metastasis (range 8 months-20 years). Four patients were diagnosed at autopsy, whereas five had brain metastasis at initial diagnosis. For the 25 children who did not have brain metastasis at initial presentation, the median interval from initial diagnosis to development of brain metastasis was 5 months (range 1-43 months). Twenty-nine (97%) had concurrent or prior history of distant metastasis. Eighteen (60%) had solitary brain metastasis. Treatment for the 26 non-autopsy-diagnosed children included surgery (S), followed by postoperative radiotherapy (RT) and chemotherapy (CT) in 2, S and postoperative RT in 1, RT and CT in 16, S alone in 2, CT alone in 2, RT alone in 1, and no treatment in 2. Median survival was 4 months after diagnosis of brain metastasis, with a 1-year survival rate of 11.5%. On multivariate analysis, only the use of RT was found to positively influence freedom from neurologic progression (p = 0.005). CONCLUSIONS Brain metastasis is uncommon in children with a diagnosis of sarcoma, neuroblastoma, or Wilms' tumor and is often accompanied by concurrent distant disease. Children treated with RT for brain metastasis had a better freedom from neurologic progression rate than those who did not receive radiotherapy.