Unscheduled absenteeism is a costly and disruptive phenomenon that remains problematic for organizations. It is imperative that managers understand more fully the antecedents and consequences of this complex behaviour. This study aims to shed light on the issue by analysing the absence trends in a large public sector organization undergoing modernization and downsizing. It is argued that employer assumptions about the legitimacy of individual absenteeism will guide decision making with regard to appropriate absence management strategies. This study highlights the danger of falsely attributing individual-level causes of absenteeism to what may be better understood as a group-level phenomenon. This phenomenon represents a predictable response in the context of major organizational change. This research has implications for human resource management strategies in organizations experiencing rapid change.