Abstract Given the absence of a clear statement from the CJEU on the horizontal effect of EU fundamental rights, this contribution takes the corresponding judgment in Association de médiation sociale as an embarkation point for an analysis of the respective case-law. In some cases, the CJEU has explicitly accepted the horizontal effect. While in these cases the source of a specific right as either a general principle of EU law or as a Charter right may not to be decisive, the content as well as the purpose of a ‘fundamental’ right within a specific context is crucial. As a consequence, the question arises as to why some fundamental rights are capable of producing a horizontal effect, while others cannot.
