The increased use of temporary contracts has instigated debates on possible implications for employees' attitudes, well-being and behaviour. The complex issues related to this debate are reviewed from a theoretical, empirical and conceptual point of view. First, the definitions of temporary employment that are currently used in OECD countries are reviewed. Second, theoretical views concerning possible determinants are elaborated. The theoretical frameworks discussed include Work Stress Theory, Social Comparison Theory and Social Exchange Theory. The determinants proposed in these theories have served to form the basis of hypotheses on differences between temporary and permanent workers on various psychological outcomes. Third, research on associations between temporary employment and the variables job satisfaction, organizational commitment, well-being and behaviour are reviewed. These variables are most frequently used in the realm of temporary work research. This review concludes that research results have been inconsistent and inconclusive, unlike the predictions that follow from the theoretical frameworks. This leads to a fourth section in which potential explanations for these inconsistent findings are advanced. In conclusion, a conceptual model is developed to inspire future research.