The aim of this article is to identify the relationship between the fulfilment of relational and transactional psychological contracts and work results, taking into account the mediation effect expressed in organisational identification. The empirical research was conducted on a group of 402 HR professionals responsible for designing and implementing HR practices in one of the leading companies of the Polish energy sector. Hypotheses were tested using the partial least squares structural equation modelling technique (PLS-SEM). Based on our research, we found that the implementation of both relational and transactional psychological contracts positively influenced the results achieved by HR professionals, both directly and indirectly, through the mediating role of organisational identification. The results indicate that the relationship between the psychological contract and work results is stronger when mediated by organisational identification. It plays an important role, especially in relation to the transactional contract. The collected results lead to the conclusion that organisations, wishing to increase the level of work results achieved by HR professionals, should as much as possible fulfil the expectations of employees and meet the commitments made to them within the framework of the established psychological contract. The study makes an important contribution to the understanding of the "priority" importance of organisational identification in enhancing the efforts of HR professionals to deliver work results that benefit both employees and the organisation.