Exercise improves physical and mental health. Nevertheless, most 20-year-olds do not exercise, and approximately 50% of the participants in exercise programs drop out in the first 3 to 6 months. In view of the health benefits of exercise, college health educators and clinicians need to be able to identify factors that predict exercise relapse in a student population. The authors administered questionnaires measuring Prochaska's 10 processes of change for exercise, self-efficacy, and decisional balance to 52 physically active undergraduate students. They assessed baseline exercise levels in October and reassessed them about 8 weeks later. At baseline, relapsers had significantly lower self-efficacy scores than those who maintained their exercise levels. The relapsers also had higher perceived negative views of exercise. These findings provide support for applying the transtheoretical model of behavioral change to a college population.