The article presents a multi-threaded analysis of the principle of promoting the work-life balance for parents and carers, which enjoys a relatively strong normative foundation in national, international and European legal instruments. First, the complex nature of the concept of work-life balance is outlined. The hypothesis according to which – from the theoretical and legal point of view – the concept of supporting the balance between work and private life can be perceived as a principle of labour law, is discussed further. Then, the influence of European law on the development of WLB programs in the field of labour law is demonstrated. In this section, particular attention is paid to Directive 2019/1158. In the last part of the analysis, the previous observations and conclusions are linked and compared with the current realities of the Polish labour market and the evolving legal system.