In a sample of 134 married couples randomly assigned to traditional or integrative behavioral couple therapy (TBCT vs. IBCT), a multivariate hierarchical growth curve analysis using latent variable regression revealed that measures of communication, behavior frequency, and emotional acceptance acted as mechanisms of change. TBCT led to greater changes in frequency of targeted behavior early in therapy, whereas IBCT led to greater changes in acceptance of targeted behavior both early and late in therapy. In addition, change in behavioral frequency was strongly related to improvements in satisfaction early in therapy; however, in the 2nd half of therapy, emotional acceptance was more strongly related to changes in satisfaction. Research and clinical implications are discussed.