Abstract Objective This study was designed to assess cognitive function, mood, aggression, and personality traits among adult men with idiopathic epilepsy. Methods Seventy-one male patients with idiopathic epilepsy were recruited from the outpatient epilepsy clinic of Assuit University hospitals. Another 58 subjects matched with respect to age, sex, and socioeconomic status formed the control group. For each participant, a complete medical history was obtained, and clinical examination, EEG, and psychometric evaluation were performed. For the psychometric evaluation, we used the Stanford–Binet test (fourth edition) to assess cognitive function, the Beck Depression Inventory to assess symptoms of depression, the Aggressive Behavior Scale, and the Eysenck Personality Questionnaire. Results Patients with epilepsy reported highly significant impairment in all cognitive measures and higher scores on depressive symptoms, aggressive behavior, and most personality traits compared with controls. Early age at onset, prolonged duration of illness, increased frequency of seizures, and history of status epilepticus were significantly negatively correlated with some of the cognitive function subscales. Conclusion Epilepsy itself and epilepsy-related factors are associated with cognitive function deterioration, depression, aggression, and some abnormal personality traits.