Sudden unexpected death in epilepsy (SUDE) remains an under-investigated area. Little progress has been made in prospective evaluation of its incidence and causes. We report an audit of Cardiff Epilepsy Unit data that identified 14 cases of SUDE within a time period of 7000 patient-treatment years. These data suggest that SUDE occurs in 1 in 500 of our patients per year. Males were affected twice as often as females. The mean age of affected patients was 35 years, and most were in the 20-40 year age bracket. Eleven had epilepsy for more than 6 years, 12 were taking one or two antiepileptic drugs, and nine had been experiencing four or fewer seizures per month. Ten patients had idiopathic generalized seizures, and only one patient did not experience tonic-clonic seizures. Antiepileptic drug usage favoured carbamazepine. Most patients were not living alone but 11 of 14 (79%) were either unmarried, separated or widowed. In comparison with other patients attending the Epilepsy Unit (more than 1820 patients), SUDE patients were significantly (chi 2 < 0.05) more likely to be male, to have idiopathic generalized tonic-clonic seizures, or to be taking carbamazepine (monotherapy or in combination with another drug). There were no statistically significant differences in age, duration of epilepsy, number of drugs, or seizure frequency between the SUDE patients and our other patients. Correct case identification, and controlled, prospective, ante-mortem studies are needed so that the true incidence, associated risk factors and causes of sudden unexpected death in epilepsy can be accurately ascertained.