External motivation, such as incentives, can encourage behavioral change and promote physical activities necessary to maintain and improve health. However, in Japan, few researches have reported on the effects of incentives on the expected increase in physical activity. This study analyzed the effect of incentives on step counts taken in the Yokohama Walking Point Program, a health initiative of the Yokohama city. We found a positive association between winning incentives and the step counts, even after controlling for personal attributes.