This study examined the contribution of cognitively-oriented adjunct treatments to assertive training. Unassertive university students (N=42) were randomly assigned within an analysis of covariance design with three levels of treatment (Cognitive Self-Statement Training (CSST), Attribution Training (AT), and Behavioral Rehearsal (BR]. Multiple measures across behavioral and cognitive domains were used to evaluate outcome. The major findings of this study suggest that a multimodal cognitive-adjunct treatment concerned with self-statements makes an effective contribution to traditional assertive training methods. Results were discussed in terms of models of assertive behavior. Treatment-related issues concerned with theory, modality, and content were also explored. (Author)