Using a prospective study of 77 1st-year psychology students' voluntary attendance at peer-assisted study sessions for statistics, the authors tested the addition of role identity to the theory of planned behavior. The authors used a revised set of role-identity items to capture the personal and social aspects of role identity within a specific behavioral context. At the commencement of the semester, the authors assessed the students' attitudes, subjective norm, perceived behavioral control, role identity, and intention. The authors examined the students' class attendance records 3 months later. Attitudes and perceived behavioral control predicted intention, with intention as the sole predictor of attendance. Role identity also predicted intention, reflecting the importance of the student role identity in influencing decision making related to supplementary academic activities.