Absenteeism at work adversely affects performance in organizations, and is reportedly complex. Absenteeism is not only a behavior caused by an individual’s characteristics, but also a system behavior of organizations, as implied in the notions of absence culture and absence norm. In this paper, it is suggested that the use of agent-based modeling and simulation can be an effective way to study mechanisms of absenteeism. To develop an agent-based simulation, a model of workers ’ mental processes related to the absence norm—which can be used as behavior rules of agents—is suggested. Finally, results of the simulation with the base model are introduced, and the interplay between the absence norm and absence rate in organizations, as well as the assimilation of workers ’ perceptions, is discussed.