Adult patients with left, right, or bilateral temporal lobe epilepsy or absence epilepsy, and normal controls completed the Buss-Durkee Hostility Inventory (BDHI), a standardized questionnaire of aggressive tendencies. Patients with left temporal lobe seizure foci scores higher on the Suspicion scale than did other patients or controls (p < 0.05). Factor analysis scale scores identified three factors: hostile feelings, covert aggression, and overt aggression. The groups differed on their pattern of factor scores (p < 0.01): patients with left temporal lobe epilepsy scored higher than other groups on hostile feelings, normal controls scored higher on Covert aggression, and bitemporal patients scores higher on Overt aggression. Patients with absence seizures did not differ from controls. Lateralization of the seizure focus in patients with temporal lobe epilepsy may alter expression of aggressive behavior.