6 males and 3 females, 2-17 years old, underwent partial or complete corpus callosotomy as treatment for medically intractable epileptic seizures. All benefited from the procedure. Evidence for unilateral cerebral damage on computerized tomography or a nonlocalized focus with secondary contralateral spread were the criteria for patient selection. The best results were obtained in atonic seizures. Long term side effects were minor and were minimized by staging the callosal resection. If partial callosotomy is effective, complete resection is unnecessary.