The European harmonisation of national criminal legislations seems not limited to their special part. Despite the doubts concerning the scope of application of Articles 83 and 325 TFEU, EU sources in criminalmattersaffectalsothegeneralpartofdomesticcriminallaw. TheauthorfocusesonthreewaysthecaselawoftheCourtofJustice influences the general part of national criminal law (the European harmonisation of fundamental principles and rights in criminal matters,theautonomousdefinitionofgeneralconceptsofcriminallawat the EU level, and the duty to disapply general rules of national criminal law in contrast with EU law having direct effect). The European harmonisation of the general part of criminal law raises several issues at the legislative, jurisprudential and scientific level, which need to be solved on the way towards a further European integration in criminal matters.