Negative attitudes toward people who have serious mental illnesses held by mental health professionals threaten the effectiveness of psychiatric treatment. In this study, attitudes held by case managers working within the public sector were investigated. Differences between supportive and intensive case managers were compared with community controls using the Opinions about Mental Illness Scale. The results showed a complex interplay among client level of functioning, type of case management approach, case management philosophy, and attitudes. Among other findings, intensive case managers held more authoritarian attitudes than did their supportive case manager counterparts.