CNS lesions of tuberous sclerosis complex (TSC) are due to a developmental disorder of neurogenesis and neuronal migration. MRI studies provide excellent in vivo demonstration of the various pathologic lesions. Symptoms of cortical tubers may include seizures, mental retardation, learning disabilities, and abnormal behavior. Seizures have a focal or multifocal origin, this clinical feature depending on the localization of the cortical tubers. Epilepsy associated with TSC is often intractable, but seizure control has benefited from the introduction of the new antiepileptic drugs. Carefully selected drug-resistant patients can be assessed with intensive monitoring as candidates for surgical removal of epileptogenic lesions. The success of epilepsy surgery is predicated on the clear identification of epileptogenic foci.