The primary aim of this article is to question whether the general anti-abuse rule (GAAR) of Anti-Tax Avoidance Directive (ATAD) is an effective tool to tackle tax avoidance. By using a comparative technique as a method, other directives that include a GAAR will be analysed as a companion to the ATAD to identify whether there is a common understanding of the concept of abuse of tax laws within the EU legal order. Then the general consequences of the application of the GAAR of the ATAD will be exposed. The difficulties which could be encountered in the application procedure will be explained around some potential scenarios, based on simple models developed by the author.