This meta-analysis examines associations between therapeutic relationship variables, and the extent to which they account for variability in treatment outcomes, in 49 youth treatment studies. Correlations between therapeutic relationship variables ranged from modest to strong. Among the best predictors of youth outcomes were counselor interpersonal skills, therapist direct influence skills, youth willingness to participate in treatment, parent willingness to participate in treatment, youth participation in treatment, and parent participation in treatment. Adequacy of current approaches to conceptualizing and measuring therapeutic relationship variables, such as the therapeutic alliance, in youth and family therapy is discussed. This paper represents the most comprehensive analysis of therapeutic relationship constructs in the youth treatment literature.