The aim of this review is to give an overview of the available evidence on the effects of financial incentives to stimulate physical activity. Therefore, a systematic literature search was performed for randomized trials that investigate the effects of physical-activity-related financial incentives for individuals. Twelve studies with unconditional incentives (eg, free membership sport facility) and conditional incentives (ie, rewards for reaching physical-activity goals) related to physical activity were selected. Selected outcomes were physical activity, sedentary behavior, fitness, and weight. Results show that unconditional incentives do not affect physical activity or the other selected outcomes. For rewards, some positive effects were found and especially for rewards provided for physical-activity behavior instead of attendance. In conclusion, rewards seem to have positive effects on physical activity, while unconditional incentives seem to have no effect. However, it should be kept in mind that the long-term effects of financial incentives are still unclear.