Use of valid, affordable, accessible, and brief measures facilitates the assessment of mental health outcomes. The Child and Adolescent Behavior Assessment Scale, a brief, structured scale, assesses problem behavior through patient and/or informant report. The purpose of this paper is to illustrate the scale's psychometric properties. In the cross-sectional study presented, a large national sample of youth (aged 5-18) admitted for psychiatric treatment (N = 32,689) was examined. The two major domains of problem behavior assessed were Internalizing and Externalizing. Reliability was good to excellent with alpha levels ranging from 0.874 to 0.917. Additional items measured Risk Behavior (α = 0.648). Subscale total scores correlated well with the Brief Psychiatric Rating Scale for Children, 9-item version (BPRS-C-9). Exploratory and confirmatory factor analyses supported the three-factor, multidimensional model of problem behavior as satisfactory for child and adolescent use, although further research is required to refine some items for clarity and improved model fit.