Dimensional models of mental disorders in community-based epidemiological samples have consistently demonstrated correlated externalizing and internalizing factors underlying common mood, anxiety, and substance use disorders. However, such analyses tend to exclude populations such as prisoners and psychiatric inpatients. As these samples have been shown to have a much higher prevalence of mental disorders and comorbidity than community samples, whether the internalizing-externalizing structure of psychopathology will replicate in such samples is unknown.The current study examined the consistency of this structure in a representative sample of 1837 prisoners through structural equation modeling of 10 common mental disorders along with a record-based index of antisocial behavior.Diagnoses were determined by administration of the Composite International Diagnostic Interview 2.1. Data were analyzed via tetrachoric correlations using the weighted least squares estimator in exploratory and confirmatory factor analyses.Results revealed that a two-factor solution, entailing correlated internalizing and externalizing factors, displayed the best fit to the data.This study provides additional support for characterizing common psychopathology in terms of internalizing and externalizing factors.