Abuse of tax law is both a complex and an ambiguous concept per se. Each country having developed its own approach, which entails differing consequences as regards domestic, EU and international tax law, abuse of tax law across Europe is a real puzzle. A thorough analysis of this concept requires both to bring out the common features shared by all domestic approaches of the countries chosen for this analysis – that is, France, Germany, Italy, Spain, and the United Kingdom – but also to describe the theoretical and practical specificities of each domestic approach. The first part of this article, which details the French and the German approaches, gives a taste of the similarities and of the differences of interpretation and practical implementation of the abuse of law concept viewed through two domestic prisms. For example, on the one hand, France and Germany both use a general concept of fraud, together with a certain number of specific anti-avoidance rules, and they both share a mostly statutory approach of the notion. On the other hand, however, the French and German approaches greatly differ on the penalty as well as on the proceedings which are applicable, whenever an abuse of law is characterized.