Cognitive-behavioral therapy (CBT) is skill based and assumes active patient participation in regard to treatment-related assignments. The effects of patient compliance in CBT outcome studies are equivocal, however, and 1 gap in the literature concerns the need re account for the quality versus the quantity of assigned work. In this study, both quality and quantity of home-based practice were assessed to better evaluate the effects of treatment compliance in patients with panic disorder (N = 48) who participated in a 12-session CBT protocol. Patient estimates of compliance were not significantly associated with most outcome measures. On the other hand, therapist ratings of compliance significantly predicted positive changes on most outcome measures. Moreover, therapist and independent rarer estimates of the quality of the participant's work, relative to the quantity of the work, were relatively better predictors of outcome.