Using histological parameters with high recognition reliability, we retrospectively analyzed all newly diagnosed patients under the age of 16 years (n = 100) with brain and spinal cord tumors presenting to the National Neuroscience Centres of the Richmond and Beaumont Hospitals, Dublin, Ireland, between 1985 and 1990, allowing analysis of 5-year survival in all cases. Tumor histology was reviewed by two neuropathologists blinded to previous histological diagnosis and to the site of lesion. We found that certain histological features such as very low cell density and microcyst formation had a positive effect on prognosis. Mitoses and pleomorphism had a negative effect on prognosis, whereas necrosis and meningeal involvement had no effect on prognosis. It is suggested that identification of reliably recognized histological features rather than assignation of tumors to particular diagnostic categories may be a more reliable predictor of tumor behavior in the pediatric age-group.