Originally, private law was considered to be immune from the effect of fundamental rights, the function of which was limited to being individual defences against the vigilant eye of the state. This traditional view, however, has recently been put under pressure as a result of fundamental rights increasingly becoming relevant for private law. The relationships between private parties under private law have started losing their immunity from the effect of fundamental rights. The major question at present is no longer whether fundamental rights may have an impact on private law, but to what extent this will occur, and the answer to this question will determine the future of private law. The primary aim of this article is to establish how fundamental rights and private law (may) relate to each other at present in different legal systems. In light of this, the article considers how fundamental rights (may) affect the relationships between private parties under private law and what consequences this effect has for the relationship between fundamental rights and private law.