Tax havens are a recent concern of many countries; they reduce public revenues by encouraging tax evasion, avoiding legal regulations and losing financial flows. As a result, tax havens increase state debt, facilitate money laundering, fuel inequalities and exacerbate financial instability. In our paper we try to approach at a theoretical level the tax haven, more precisely, the definition of the concept itself and the main ways of supply (through tax optimization / tax evasion, transfer pricing, etc.), the issue of tax compliance (a cause of tax haven development is lack this compliance), as well as the presentation of the situation of tax havens at international level.The methodology used is a descriptive one, using various bibliographic sources, mainly from foreign literature - scientific articles, relevant books in the field of reference, legislation, analysis and studies, official documents of various international tax institutions.