Many adolescent substance abusers enter treatment because of external pressures and thus lack motivation to change their behavior and engage in treatment. Because an understanding of adolescent motivation may contribute to improved treatment, an investigation of factors that predict motivation was undertaken with youth admitted to an adolescent outpatient substance abuse treatment program (N=196). At admission, these subjects received a comprehensive biopsychosocial assessment. Using multiple regression analysis, factors considered to potentially predict motivation were assessed. Of the factors examined, those that involved experiencing various negative consequences of substance use emerged as important predictors of motivation, whereas severity of substance use did not. Diminished awareness of negative consequences of use was consonant with lower motivation, suggesting the importance of interventions to help youth recognize negative consequences of their substance use. Interventions to enhance motivation are likely to become more important as the juvenile justice system increasingly refers troubled youth to treatment.