Predictions of family therapy outcome consistently vary depending on which client rates the alliance. We used the actor-partner interdependence model (Kenny, Kashy, & Cook, 2006) to test the interdependence of parents' and adolescents' ratings of alliance, session depth/value, and improvement-so-far after Sessions 3, 6, and 9. Initial analyses found trivial between-therapists variance; therefore, a 3-level hierarchical model partitioned the variance in these variables into between families, between family members, and between session components. For alliance and session depth, results showed a significant parent actor effect and a significant adolescent partner effect. Specifically, when parents saw a stronger alliance, they also saw the session as more valuable, but when adolescents saw a stronger alliance, their parents saw the session as less valuable. Both the parents' and the adolescents' improvement scores showed significant linear growth over time, and adolescents' alliance ratings were positively associated with their own and their parents' views of therapeutic progress. (Contains 2 tables.)