The Beck Cognitive Insight Scale (BCIS; Beck, Baruch, Balter, Steer, & Warman, 2004) was administered to 42 (28%) inpatients with psychotic disorders, 52 (35%) with a bipolar disorder, and 56 (37%) with a major depressive disorder (MDD). The hypotheses were (a) that the mean level of cognitive insight in a psychotic or a bipolar disorder is lower than that in a MDD, (b) that the mean levels of cognitive insight in psychotic and bipolar disorders were comparable, and (c) that the mean BCIS index score for a bipolar disorder in which the most recent episode had been mania is lower than the mean BCIS index score for a bipolar disorder in which the most recent episode had been mixed or depressed. All three hypotheses were supported. The results were discussed as supporting cognitive insight as a psychological construct that varies predictably according to the nature of a psychiatric disorder.