Research on the effectiveness of short-term education programs in changing societal attitudes about mental illness has been mixed. Education efforts seem to be mediated by characteristics of the program participants. This study determines whether the effects of a specially prepared, semester-long course on severe mental illness are mediated by pre-education knowledge about and contact with severe mental illness. Eighty-three participants who were enrolled in either a course on severe mental illness or general psychology completed the Opinions about Mental Illness Questionnaire before beginning the course and at completion. Research participants also completed a pre- and posttest of knowledge about mental illness and a pretest on their contact with people who have severe mental illness. The education program had positive effects on some attitudes about mental illness. Interestingly, the effects of education group interacted with pre-education knowledge and contact and varied depending on attitude. Participants with more pre-education knowledge and contact were less likely to endorse benevolence attitudes after completing the education program. Participants with more intimate contact showed less improvement in attitudes about social restrictiveness. Implications of these augmentation and ceiling effects are discussed.