This paper deals with the relationship between social security law, a branch of public law that bears many features of private law, and labour law, a branch of private law that bears features of public law. There is countless feedback between the two branches. The paper focuses particularly on the issue of important personal obstacles to work on the part of an employee, in the regulation of which the two branches are closely interconnected in terms of subject-matter. While labour law regulates an employee’s right to be provided time off from work by an employer when these obstacles to work arise, social security law regulates the right to material welfare of an employee. The relationship between the branches is examined in the context of a brief analysis of the main issues of social security law and labour law. When examining the relationship between private and public law, we will arrive at the conclusion that the dualism between private and public law is increasingly more relativized.