Aim: There is a lack of knowledge about how adolescents with substance abuse problems manage after taking part in treatment. It is also difficult to perform traditional follow-up studies with this group. This article presents the outcome of a prospective study of 455 adolescents who underwent outpatient treatment, based on data taken from official registers. It aims to describe and analyse indications of continued use of substance (CUS) and how various risk and protective factors predict outcomes after initiated treatment at a Maria clinic in Sweden. Design: The study is based on structured interviews at intake, and the data that indicated CUS were taken from several different national registers. The analyses included descriptive data and bivariate associations, logistic regressions and a CHAID analysis. Results: Almost two thirds of the adolescents have no indication of CUS at one-year follow-up. The ten studied risk factors independently were weak predictors of CUS and it was instead the accumulation of risk factors that were linked to a negative outcome. Conclusion: The majority of adolescents who start outpatient treatment for substance abuse problems return to a lesser extent in registers that may indicate a continued problem with alcohol and drugs one year later. A concentration of more than five risk factors appears to be associated with a registration. The study also provides an example of an alternative method for following up adolescents with alcohol and drug abuse problems.