A social investigation was performed of 74 patients with temporal lobe epilepsy resistant to medication, who underwent unilateral temporal lobectomy 1960-1969. The patients were compared to their sibilings and to the general population in Denmark. Comparatively many patients were born out of wedlock. The level of schooling achieved was lower than expected, and this was most pronounced in patients with an early onset of epilepsy. The number of patients having received further education was also smaller than calculated. At the time of the operation all patients were socially incapacitated by their epilepsy; this was most pronounced in males, of whom 30 per cent were institutionalized and 32 per cent were receiving disablement pension; at follow-up the figures were 6 per cent and 52 per cent, respectively. Working capacity was markedly improved postoperatively, and at follow-up 39 per cent were in full-time employment. Relief from seizures (or almost complete relief), normal intelligence, normal psychiatric status, and operation before the age of 18 years were factors which favourably influenced the postoperative working capacity. The majority of the patients were unmarried or divorced, and few of the group had children. Their housing conditions were inferior to those of their siblings and of the general population. Parental social class distribution showed an excess in the highest and lowest social classes compared to the Danish population. The patients were subjected to downward social mobility, presumably caused by their illness, as their siblings displayed an upward mobility, which was most marked in the females.