Pioneer investigators in Nigeria have presented a gloomy picture of epilepsy as a highly infectious and disastrous disease in the eyes of the public. As a result, epileptic persons suffer untold social deprivations and discrimination in education, employment, housing, marital life, etc. These assertions have been repeated over the years more as a result of incidental observations while reviewing hospital cases than as products of attitude research on the subject. We assumed, therefore, that these statements should be considered as impressive hypotheses needing to be tested. By employing the Osgood semantic differential and the behavioral differential of Triandis, we assessed the attitude of the normal literate general public toward persons with epilepsy and "cured" psychotic patients and how closely the public would associate or socialize with these people. We also inquired into the public's opinion about the causes of epilepsy and psychosis, since this knowledge is necessary for attitude formation and change. On the whole, the general attitude toward epileptic patients is negative, and toward "cured" psychotic patients, positive. There are sex differences, in that males perceive epileptic patients more favorably than females do. However, both males and females would discriminate against both the epileptic and "cured" psychotic person in terms of employment, residential accommodation, friendship, and marital relations. The major perceived causes of epilepsy reported were heredity, witchcraft, and brain damage, in that order, not infection. About 25% admitted ignorance of the cause of epilepsy, as against 1% for psychosis. The psychoses were reportedly caused mainly by Indian hemp smoking, drug abuse, brain damage, and witchcraft, in that order.(ABSTRACT TRUNCATED AT 250 WORDS)