The latent structure, reliability, and validity of the Behavioral Inhibition/Behavioral Activation Scales (BIS/BAS; C. L. Carver and T. L. White, 1994) were examined in a large sample of outpatients (N = 1,825) with anxiety and mood disorders. Four subsamples were used for exploratory and confirmatory factor analyses. In addition to generally upholding a latent structure found previously in nonclinical samples, results indicated measurement invariance of the BIS/BAS between genders and a higher order structure of the BAS scales. Convergent and discriminant validity of the BIS/BAS were supported by findings that the subscales correlated most strongly with measures of neighboring personality constructs (e.g., BIS with neuroticism, BAS with positive affect) than with measures of current anxiety and depression symptoms. Overall, the results support the psychometric properties of the BIS/BAS in this clinical sample.