Abstract The World Psychiatric Association promotes global anti-stigma programs. However, evaluation research is crucial to developing effective programs. The present study examined the effects of a lecture on mental health on public attitudes towards mental illness. Subjects were recruited from individuals employed by private companies and the government. Attitudes towards mental illness were measured using the Mental Illness and Disorder Understanding Scale developed by the authors and the Scale of Negative Attitudes Towards the Independence of People with Mental Disorders. Test scores obtained before and after the lecture were compared. The results demonstrated that scores on both scales improved significantly. The present study suggests the effectiveness of this type of educational program in reducing stigma attached to mental illness and disorder.