During a period of 42 months, we studied the prevalence of epilepsy in a specific health district, composing by four towns with 98,405 inhabitants older than 10 years. This has been accomplished by a two-phase cross-sectional study. The prevalence rate observed was 4.12/1000 inhabitants for all types of epilepsy. No significant differences were found between the sexes. Sixty-three per cent of affected individuals had partial seizures, with a confirmed cause in 45%. Fifty-five patients with single unprovoked seizures, were also identified but not included in the prevalence rate.