The concept of cognitive insight was introduced in 2004 to describe the capacity of patients with psychosis to distance themselves from their psychotic experiences, reflect on them, and respond to corrective feedback. The Beck Cognitive Insight Scale (BCIS) was developed to evaluate these aspects of cognitive flexibility and to complement scales that describe the lack of awareness of mental illness and its characteristics. The BCIS has generated a moderate research literature, which is the subject of the current review. Several independent groups have demonstrated that the BCIS is reliable, demonstrates convergent and construct validity, and distinguishes patients with psychosis from healthy controls and patients without psychosis. While the majority of the studies have focused on the relationship of the BCIS to delusions, several have examined its relationship to negative symptoms, depression, anxiety, and functional outcome. Cognitive insight has predicted positive gains in psychotherapy of psychosis, and improvement in cognitive insight has been correlated with improvement in delusional beliefs. Finally, preliminary findings relate neurocognition, metacognition, and social cognition, as well as reduced hippocampal volume to cognitive insight. A heuristic framework is presented to guide future research.