The Cognitive Checklist for Mania-Revised (CCL-M-R), which measures the severity of maladaptive beliefs and cognitions associated with mania, was administered to 35 inpatients with a major depressive disorder, 20 inpatients with a schizoaffective disorder, and 45 inpatients with a bipolar I disorder to determine whether cognitions associated with mania differentiate patients who have most recently experienced either manic, mixed, or depressive episodes. The CCL-M-R is composed of four subscales assessing (a) exaggerated beliefs about self-worth (Myself), (b) grandiose beliefs about interpersonal relationships (Relationships), (c) erroneous beliefs about needing excitement from engaging in high risk situations (Pleasure/Excitement), and (d) unrealistic beliefs about having high energy levels for undertaking goal-driven activities (Activity). As hypothesized, the mean CCL-M-R total, Myself, Relationships, and Activity scores of the 26 patients with manic episodes were higher than those for either the 17 patients with mixed episodes or the 57 with depressive episodes. The CCL-M-R was discussed as a reliable and valid instrument for measuring the severity of maladaptive cognitions associated with mania in psychiatric patients.