This study sees to explore what motivates undergraduate student employees in academic libraries. The literature contains many anecdotal accounts of motivation programs and incentives employed in academic libraries but very few empirical studies concerning these employees. This study explored student employee motivation within the framework of self-determination theory: measuring levels of intrinsic motivation, internalized regulation, introjected regulation, and external regulation. A questionnaire was distributed to student employees at seven ARL member libraries. The questionnaire gathered demographic data and used the Motivation at Work Scale (MAWS) to measure their motivation. The study found that students showed higher levels of intrinsic motivation and external regulation, and while students' majors do not have a notable effect on their motivation, the task they perform at work does impact their motivation. The results of this study can be applied to design and implement more effective motivators and incentives for student employees in academic libraries.