The purpose of this study was to examine whether undergraduates' participation in 12 different leadership trainings, workshops, conferences, or programs was associated with students' leadership efficacy. We used data from the Multi-Institutional Study of Leadership survey, which eight of the Big 10 institutions administered to students in spring 2018. The results suggest that students' participation in shorter-term or moderate-term experiences--a leadership conference, retreat, lecture/workshop series, course, or positional leadership training--was positively associated with students' leadership efficacy. We therefore encourage leadership educators and practitioners in higher education to consider the duration of their programs to maximize students' outcomes.