An increasing number of product returns accompanies growing e-commerce sales, and is a major burden for companies but also for the environment. This paper analyzes the effect of gamification on return motivation (RM) and purchase motivation (PM). Drawing on self-determination theory by Deci & Ryan (1985), we designed a consumer-centric gamification scenario to investigate whether gamification can influence return motivation in terms of sustainability. Furthermore, we elaborate participants’ autonomy (A), competence (C), and relatedness (R) need satisfaction through gamification. A survey-based online experiment with online shoppers from the U.S. (n=973) is analyzed using a structural equation model (SEM). Among other results, we show that gamification has a strong direct effect on return motivation. We conclude that gamification acts as extrinsic motivation. Our results indicate that gamification is a promising tool to sensitize consumers for sustainable online shopping behavior.