This investigation examined how personal, environmental and substance use factors predicted psychosocial functioning for youth with alcohol and drug problems. Four hundred twenty-four adolescents (M = 15.9, SD = 1.3) completed comprehensive assessments, including personal characteristics (e.g., Axis I diagnosis, motivation, self-esteem), environmental factors (e.g., family history, social supports) and substance use, at study intake and throughout the year following inpatient treatment. Treatment outcomes were assessed by measures of academic functioning, family relations, social functioning as well as health status and mental health treatment at one year. Aspects of the proposed model significantly predicted all treatment outcome domains, except family functioning, in the year following treatment. Psychosocial functioning at one year was predicted by age, gender, SES, comorbid psychopathology, family influence and nonusing social supports prior to treatment and relapse status after treatment. The utility of variables associated with substance use treatment outcomes in predicting psychosocial outcomes is considered. (Contains 1 table.)