This study investigates the relationship between outcome expectancy for an individual stress management course and the total perceived impact of a comprehensive stress management intervention (SMI). It is based on data from 3 different measurement points from a longitudinal SMI in Switzerland. Individual and organizational outcome expectancies for stress management courses were captured with 2 newly developed items (SMI outcome expectancy) immediately after course completion. Perceived individual and organizational impacts of the overall intervention captured with 2 items of a retrospective impact assessment scale (perceived SMI impact) at the 2-year follow-up survey were used as the outcome measurement. Baseline individual and organizational change commitments (as rated by participants) were included in the analyses as possible moderators. Regression analyses show that individual and organizational outcome expectancies with respect to stress management courses can to some extent predict the perceived impact of the intervention as a whole. At the individual level, an intervention will be perceived as most successful when participants already have a high individual change commitment and develop high outcome expectancies during stress management courses.