Psychotherapists often describe patients who present management problems as "difficult patients." This article describes a 5-factor scale to measure how therapists perceive difficult psychiatric patients. Reliability and validity evidence is presented for scales labeled Demanding, Help Rejecting, Unreachable, Dangerous, and Poor Fit. Fifty-four psychiatric outpatients identified as difficult to treat by two or more therapists were compared with 54 control psychiatric outpatients matched on age, sex, marital status, and diagnosis. Therapists rated difficult patients higher on each scale. Patients rated higher on the Demanding, Help Rejecting, and Poor Fit scales were heavier and more varied users of the treatment system than were those rated lower on these scales. The scale helps identify causes of staff dissatisfaction and inappropriate organization of services and suggests how to meet the special needs of difficult patients. Problem patients can be seen as denying the competence and authority of the mental health professional but also as central to the unique mandate of psychiatry. The reward system should more adequately support those therapists who care for the patients often avoided by others.