Little is known about the nature of the relationship between the alliance and client involvement in child psychotherapy. To address this gap, we examined the relationship between these therapy processes over the course of cognitive-behavioral therapy (CBT) for child anxiety disorders. The sample was 31 child participants (M age = 9.58 years, SD = 2.17, range = 6-13 years, 67.7% boys; 67.7% Caucasian, 6.5% Latino, 3.2% Asian/Pacific Islander, and 22.6% mixed/other) diagnosed with a primary anxiety disorder. The participants received a manual-based individual CBT program for child anxiety or a manual-based family CBT program for child anxiety. Ratings of alliance and client involvement were collected on early (Session 2) and late (Session 8) treatment phases. Two independent coding teams rated alliance and client involvement. Change in alliance positively predicted late client involvement after controlling for initial levels of client involvement. In addition, change in client involvement positively predicted late alliance after controlling for initial levels of the alliance. The findings were robust after controlling for potentially confounding variables. In CBT for child anxiety disorders, change in the alliance appears to predict client involvement; however, client involvement also appears to predict the quality of the alliance. Our findings suggest that the nature of the relationship between alliance and client involvement may be more complex than previously hypothesized. In clinical practice, tracking alliance and level of client involvement could help optimize the impact and delivery of CBT for child anxiety.