The main purpose of this article is to study the concept of tax evasion by reference to the Specialty literature, as well as to the current and past regulatory framework in Romania. It can be noticed that, an official definition is not attributed by the law in force to the phrase "tax evasion", which mainly deals with the manifestations of the phenomenon and the penalties and sanctions applicable in case of violation of the law. In this context, this article presents a self-defined definition of tax evasion, including by reporting and delimiting it against neighboring concepts, namely abuse of law, avoidance of taxation, informal economy and tax fraud.