In the first meta-analysis of studies assessing insight in mania, we sought to determine whether insight in mania is state-dependent or a trait-like condition. In schizophrenia, insight is a trait-like condition. If state-dependent, insight in mania would differ from insight in schizophrenia, and different treatment and research implications would follow. Seven reports using standardized insight rating scales in mania were identified through a MEDLINE literature search. Four longitudinal studies were included in a meta-analysis. The meta-analysis found that insight appears to be state-dependent. Insight showed a 20% improvement (95% confidence intervals, 7% to 34%) after recovery from acute mania (p = .003). Insight improves in bipolar disorder with resolution of the acute manic episode, suggesting that insight is state-dependent in bipolar disorder. We suggest that impaired insight be considered as part of the diagnostic picture of acute mania.