Although studies have shown that supplemental instruction (SI) programs can have positive effects in introductory accounting courses, these programs experience low participation rates. Thus, our study is the first to examine the factors leading to student participation in SI programs. We do this through a survey instrument based on the Theory of Planned Behavior. Our study shows that students' attitudes toward the sessions affect their intent to participate in them. This attitude is influenced by students' perceptions that the sessions can help them in various ways. Results also show that influential others can influence student intent to participate in SI sessions. We also note that students' perceptions of the amount of personal control that they have over going to SI sessions have no effect on their participation in the sessions. We discuss how these findings can be leveraged to increase SI participation rates.