Many economic evaluations have been conducted for adult substance abuse treatments, but only a few have been conducted for adolescent-specific treatments. This is the first article to present rigorous methodological guidelines for estimating the economic costs and benefits of adolescent substance abuse treatments while also addressing the potential challenges associated with such research activities. A representative case study of two adolescent substance abuse treatment programs (one residential and one outpatient) is presented to show some of the initial steps of a comprehensive economic evaluation (e.g., cost analyses, selection of treatment outcome measures, and valuation of outcome measures via monetary conversion factors). Cost data were collected and analyzed using the Drug Abuse Treatment Cost Analysis Program. Monetary conversion factors were obtained and presented for a variety of treatment outcomes. The methodological guidelines, discussion of analytic challenges, and recommendations set forth in this article provide a foundation for future economic studies on adolescent substance abuse treatments.