Encouraging and facilitating homework completion is a core cognitive behavior therapy (CBT) skill. Consequently, it represents an important part of training practitioners. Oftentimes the process of integrating homework into therapy is rushed, poorly executed, or forgotten, and trainees are surprised to find that some patients do not complete homework. We advocate for increased therapist responsibility in accounting for homework nonadherence. Therefore, problems with the use of homework in therapy are frequently an agenda item in the supervision of trainee cognitive behavior therapists. In our experience, trainee CBT practitioners exhibit a number of interrelated automatic thoughts, assumptions, and in-session behaviors that influence their use of homework assignments. The Cognitive Behavior Therapy Homework Project has proposed a "model for practice" to guide the use of homework in CBT [Kazantzis, N., MacEwan, J., & Dattilio, F. M. (2005). "A guiding model for practice." In: Kazantzis, N., Deane, F. P., Ronan, K. R., & L'Abate, L. (Eds.), "Using homework assignments in cognitive behavior therapy" (pp. 359-407). New York: Routledge]. The present article will draw from those practice recommendations and discuss the role and impact of the therapeutic relationship and therapist beliefs on the use of homework assignments, with reference to the different levels of CBT conceptualization. Clinical examples from the supervision of trainees enrolled in the practicum component of the Massey University Postgraduate Diploma in Cognitive Behavior Therapy are used to illustrate supervising the use of homework assignments. (Contains 2 figures.)