The authors review 42 consecutive cases of benign astrocytic and oligodendrocytic tumors of the cerebral hemispheres in children undergoing surgery in the pediatric service of the Hôpital des Enfants Malades between 1975 and 1987. Epilepsy was the presenting sign in 76% of the children and remained the only clinical sign at diagnosis in 62%. Partial or complex partial seizures were observed in half of the cases, but other seizure types were also frequent. Diagnosis of the tumor as the etiological agent rested upon the results of computerized tomography or magnetic resonance imaging. Postoperative mortality (5%) and morbidity (16%) rates were low. The postoperative intelligence quotient was above 80 in 71% of the patients, and 77% of the children had no major problem in school. Although only two of the 42 patients were given postoperative radiotherapy, there were no recurrences in 82% of the survivors. The actuarial probability of nonrecurrence of the tumor was 95% at 5 years. Three patients with recurrent tumor underwent further surgery and are, at the present time, recurrence-free. The incidence of epilepsy fell from 76% before surgery to 19% after removal of the tumor alone; therefore, intraoperative electrocorticography and resection of the electrically abnormal cortex at the time of the first surgical procedure do not appear necessary. It is possible that tumor removal restores a mechanism that limits the spread of seizures and, thus, the clinical manifestations of epilepsy. Benign astrocytic and oligodendrocytic tumors of the cerebral hemispheres in children should not be treated with adjuvant radiotherapy, at least initially.