<p>Incentives and green nudges are increasingly used as policy instruments to promote pro-environmental behavior and encourage sustainable lifestyle change. However, their relative effectiveness and underlying behavioral mechanisms remain insufficiently understood. Drawing on the Theory of Planned Behavior, this study examines and compares the direct and moderating effects of economic incentives and green nudges on college students’ pro-environmental behavior. Using survey data from 384 university students, the results show that attitudes and perceived behavioral control significantly predict sustainable behavior, whereas subjective norms have no significant effect. Green nudges demonstrate a positive direct effect on behavior, suggesting that subtle modifications to the campus choice environment can effectively facilitate sustainable daily practices. In contrast, incentives exhibit a negative direct effect but positively moderate the relationship between attitudes and behavior, indicating that incentives are more effective at reinforcing existing environmental commitment than independently motivating sustainable action. No significant moderating effect was found for green nudges. By comparing incentives and green nudges within a unified behavioral framework, this study highlights their distinct motivational and contextual mechanisms. The findings suggest that universities should prioritize low-cost and non-coercive green nudges while carefully designing incentive systems that support rather than undermine intrinsic environmental motivation.</p>