The assessment of maladaptive family functioning among adolescent drug abusers is particularly important because maladaptive family functioning has been linked to adolescent drug abuse/delinquent behaviors, and there are now highly effective family interventions available for treating these family dysfunctions. The purpose of the study reported in this article was to investigate the degree to which the Problem Oriented Screening Instrument for Teenagers screen for the family domain provides useful information regarding family functioning when used with clinic-referred youths with behavior problems. Participants in this study were 135 Hispanic and African-American youth referred for the treatment of severe behavior problems, including drug use. Our findings provide support for the usefulness of the 11-item POSIT family functioning screen. Data supporting the criterion validity of the POSIT Family screen, its ability to classify families correctly in terms of their family functioning, and its significant loading on the latent variable resulting from a confirmatory factor analysis all lend support to the usefulness of this screen of family functioning. In addition, analyses designed to explore the relationships between gender and race/ethnicity and the POSIT Family subscale showed that differences in scores by gender and race/ethnicity are not unique to the POSIT, but rather reflect similar differences in family functioning reported by the adolescent on more extensive family measures.