A substantial proportion of college students have always worked while pursuing their college degree. However, despite decades of research on working college students, very little consensus has emerged about the effect of work on college student development. This study analyzes Wabash National Study (WNS) data from 2,931 first-year students at 19 institutions to examine the effect of work on leadership skill development. Findings show that, after accounting for the effect of precollege characteristics and college engagement experiences, work can have a substantial positive effect on leadership development. Off-campus employment proved to be particularly influential even though extensive off-campus work simultaneously undercut the effect of peer interaction and cocurricular involvement on leadership. (Contains 4 tables and 2 figures.)