Three questions guided a literature review of the transtheoretical model (TTM) as applied to exercise to address the evidence for stage-matched interventions, the description of priority populations, and the identification of valid TTM measurement tools. One-hundredand-fifty studies were reviewed. Results indicate preliminary support for the use of stage-matched exercise interventions. Most studies have focused on White, middle-class, female populations, limiting the generalizability of their findings. Valid and reliable measures exist for stage of change, decisional balance, processes of change, self-efficacy, and temptations to not exercise; however, more research is needed to refine these measures. Evidence for the construct validity of the TTM as applied to exercise is mixed. When designing and implementing TTM-based exercise interventions, practitioners and policy makers are encouraged to clearly define the term exercise, choose a valid and reliable staging tool, and employ all TTM constructs and not just stage membership.