Although most patients with epilepsy lead normal lives with few or no cognitive or psychiatric alterations, a substantial minority of epilepsy patients experience neurobehavioral problems that can significantly disrupt employment, school, family life, and other aspects of daily living. This article provides a comprehensive review of neurobehavioral changes seen in patients with epilepsy, including cognitive dysfunction and psychiatric disturbances. The cognitive problems most commonly found are deficits in attention, concentration, memory, and word finding. Psychopathology in epilepsy may be manifested as depression, anxiety, psychoses, and/or aberrant personality traits. Risk factors for cognitive and psychiatric changes, etiology of cognitive deficits, localizing patterns, cognitive effects of antiepileptic drugs, and treatment suggestions are also presented.