The article explores the comparison on the ne bis in idem principle between the Constitutional Court, the Italian judges and the European Courts, in particular following the change in the jurisprudence of the European Court of Human Rights in 2016, which the Constitutional Court implemented with ruling no. 43/2018. In particular, it intends to verify the scope of this principle in Italy as of today, first of all circumscribing its scope and highlighting the difficulties encountered, essentially due to the autonomy of criminal and tax proceedings and their lack of coordination. Finally, in the perspective of the necessary intervention of the legislator in this matter, it envisages a possible overcoming of today’s problems if the criminal sanction is reserved only to tax offences characterized by fraudulent conduct.