To assess the diagnostic value of brain scanning in pediatrics, results in 556 children were analyzed. Follow-up data were available in 409 children. Of these, 37% had brain scans done because of seizures; other frequent indications were motor abnormalities (7.4%), headache (5.0%), suspected optic neuritis (4.9%), raised intracranial pressure (4.9%), and trauma (4.7%). Fifteen percent of the scans were abnormal, most often because of tumors of the brain, pituitary fossa, brain stem, and cerebellum; subdural collections; cerebral abscess; and encephalitis. Three scans were false-positive; 12 patients with tumors had normal scans. Scans were graded according to the extent they changed the a priori diagnosis. They were found most useful in patients suspected of having posterior fossa disease, raised intracranial pressure, generalized encephalopathy or metastases, and after trauma, and least useful in cases of generalized seizures and mental or behavioral abnormalities.