The present study examines the relationship between Perceived Organizational Support (POS) and work outcomes (work engagement and organization citizenship behaviour) with affective commitment as a mediator and psychological contract breach as a moderator. Drawing from data collected among a sample of nurses (N = 475), we found that affective commitment mediates the positive relationships between POS and work outcomes. Moreover, perception of unfulfilled expectations (psychological contract breach) qualifies POS-work outcome relationships such that the relationships between POS and outcomes are stronger in case of low contract breach perceptions. Implications for theory and practice are discussed.