Twenty-five patients underwent anterior corpus callosotomy (ACC) for treatment of uncontrolled seizures. Two patients died, and 6 patients experienced perioperative complications which resolved. A statistically significant reduction of generalized tonic-clonic seizures (17 patients; P less than 0.05) and complex partial seizures (11 patients; P less than 0.05) occurred following ACC. A single patient with atonic seizures became free of atonic seizures. Two patients had a greater than 50% reduction in seizures resulting in falls, a single patient became free of episodes of status epilepticus, and in 2 patients the seizures changed from generalized tonic-clonic seizures to hemiconvulsive seizures. Thus ACC appears to decrease the severity and frequency of disabling seizures in some patients with uncontrolled seizures.