The relationship between substance use, mental health disorders, and delinquency among youth is well documented. What has received far less attention from researchers is the relationship between these issues among truant youth, in spite of studies that document truants are a population at risk for negative outcomes. This study bridges this gap by (a) examining psychosocial functioning and delinquency among truants and (b) assessing the efficacy of a brief intervention (BI) in reducing delinquent behavior over time. To meet these objectives, data were collected from 183 truant youth enrolled in an ongoing National Institute on Drug Abuse (NIDA)--funded BI project. Informed by a developmental damage perspective, a structural equation model was formulated and estimated. Interim results provide overall support for the model and suggest that the BI may be a promising, innovative intervention for truant youth. Service delivery implications and directions for future analyses are discussed. (Contains 5 tables, 1 figure, and 1 note.)