This study investigates the effects of job insecurity on four organizationally important outcomes: in-role behaviour, organizational citizenship behaviour, turnover intention, and absenteeism. A model is tested in which job insecurity is simultaneously a hindrance and a challenge stressor. In particular, job insecurity is proposed to have a predominantly harmful effect on performance, turnover intention, and absenteeism, and it is argued that these effects are mediated by (reduced) work attitudes. In addition, job insecurity is also assumed to affect these behaviours in the opposite way (i.e. a suppressor effect) because job insecurity might motivate employees to make themselves more valuable to the organization by working harder and being less absent. The model is tested with a sample of 136 German non-managerial employees. Data from supervisors (i.e. in-role behaviour and organizational citizenship behaviour), the company's personnel files (i.e. absenteeism), and self-reports (i.e. job insecurity, work attitudes, turnover intention, in-role behaviour, and organizational citizenship behaviour) were used. Structural equation modelling showed that a model that included both negative and positive effects fitted the data best. The negative effect was stronger than the positive effect. The results show that the effects of job insecurity are more complex than previously assumed. In addition, the results also extend previous research into hindrance and challenge stressors because they show that stressors should not be categorized as either hindrance or challenge. Instead, it might be more appropriate to conceptualize hindrance and challenge as two dimensions.