Abuse of law in the context of EU law has been a subject of some debate. In recent cases the European Court of Justice has shown a tendency towards mixing different approaches from earlier judgments. This article takes a critical view of this development. It points out that, relating to abuse in the context of EU law, two groups of cases can and should be distinguished: on the one hand, the inappropriate use of a provision of EU law, and, on the other hand, the inappropriate use of national law with the help of EU law. This differentiation has an impact on the handling of abuse cases. It is the decisive factor in deciding how to introduce the concept of abuse into the application of law. Furthermore, it affects the answer to the question if national law or a general principle of EU law is to be applied.