A door-to-door survey to detect commonly occurring neurologic diseases was carried out in Igbo-Ora, a large Nigerian town with a population of approximately 20,000. Effective health care facilities have been operating in the community since 1963. Primary health care workers and nondoctor personnel administered a complete census, a screening questionnaire, and a simple screening neurologic examination. The pretested screening questionnaire had been shown in a pilot study to have a sensitivity of 95% for identifying those with epilepsy. Individuals positive on the screening phase of the survey were evaluated by neurologists and neurosurgeons, who used well-defined criteria to make the diagnosis. There were 101 (48 males and 53 females) who suffered from active epilepsy (5.3 cases/1,000) on prevalence day. The highest age-specific prevalence ratios occurred in those below age 20. The most common of the identifiable seizure types was complex partial seizures (52 cases). The prevalence ratio of epilepsy in this Nigerian town (with an effective health care system) is similar to that reported in some developed countries and several times lower than figures derived from studies in developing countries. These data suggest that an improved health care system would probably reduce the prevalence and burden of epilepsy in developing countries.