Abstract Physical activity has known positive effects with respect to improving health and reducing depression. While exercise also has some putative benefits for decreasing smoking, its effects on illicit drug use are relatively untested. Exercise may serve as a healthy substitute behavior for drug use. However, the majority of substance abusers are sedentary, and few individuals successfully initiate or maintain exercise regimens. Contingency management (CM) interventions are highly efficacious in reducing drug use, and growing evidence suggests these treatments can be adapted to alter a number of behaviors, including physical activity or exercise. We have pilot data suggesting that substance abusing patients who engage in exercise to earn reinforcement have improved drug abuse treatment outcomes compared to those who do not engage in exercise during CM treatments. Further, we have developed a CM-based exercise intervention, and our pilot data suggest that patients respond favorably to this intervention and begin exercising regularly. In this study, we plan to evaluate the efficacy of this exercise-based CM intervention. A total of 120 cocaine abusing patients in intensive outpatient treatment will be randomly assigned to one of two conditions: (a) standard care plus CM for completing goal-related activities not related to exercising (e.g., improving work, family, or transportation issues), or (b) standard care plus CM for completing exercise- related activities. Each intervention will consist of one weekly individual therapy session for 16 weeks, and patients in both conditions will earn the chance to win prizes for completing activities. All participants will provide urine and breath specimens 1-2 times weekly that will be tested for stimulants, opioids, marijuana and alcohol. Physical activity levels, drug use, psychological symptoms, and subjective and objective indicators of health (body mass index, waist circumference, blood pressure) will be measured pre-treatment and at months 2 and 4 (post-treatment), as well as at 6-,9- and 12-month follow-up evaluations. Compared to those receiving goal-related CM activity contracting, we expect that those in the exercise CM condition will participate in more physical activities and develop greater strength and flexibility, decrease drug use to a greater extent, reduce depressive symptoms, and improve health indices.