Changing employment relations between employees and employers due to the increasing employment flexibility have contributed to the development of a new paradigm to analyze these relations based on the concept of psychological contract. This paradigm might be particularly relevant in Poland where the employment flexibility understood as the number of workers with temporary contracts is the highest in Europe. In this paper the concept of psychological contract is presented along with the existing findings related to its range, balance and contract fulfilment vs. contract breach. The results of studies showing the differences in psychological contract of temporary and permanent workers are also presented. The majority of them indicate that psychological contracts of temporary workers are limited in their extent, less balanced and asymmetric (to workers’ disadvantage), as well as more transactional in their nature than those of permanent workers. The temporary workers’ well-being and attitudes towards work and their reaction to psychological contract breach largely depends on their preferences for this type of employment, on their qualifications and on a labor market situation. Med Pr 2016;67(4):529–536