The aim of this paper is to present the central-topics of psychological contract theory, focusing on the relevant labour law contexts. The main research method used is an examination of relevant studies, articles and monographs on the topic, a secondary analysis of empirical research data systematically compiled by the authors, and an exploration of the main labour law aspects and contexts. The difference between an employment contract and a psychological contract is that while the former is a written, legally binding contract, the latter is a theoretical, abstract construct that contains the mutual and implicit expectations of the parties. A psychological contract therefore falls into the category of "extra-legal" contracts, but in certain cases, especially in the event of breach of contract, it may have legal relevance.