The tax on the non-residents incomes has become a more present issue, because the new economical and political conjuncture, and especially because of the European one, the foreign companies intending to invest more in Romania. Through Romania’s adhering to the European Union the volume of foreign investments in Romania knew an important increase, and, implicitly, the incomes obtained by non-residents from the activities unfolded in Romania, having as consequence the increase of the tax volumes cashed from this sector. This under the conditions of a favorable fiscal treatment applied to the investors from the European Union compared to the non-residents from the extra-communitarian area. The problem of the tax applied to the incomes of the non-residents knows a few important changes, brought by Romania’s adhering to the European Union, such as, for example, those regarding the tax levels and tax exemption, the new Fiscal Code basing on protecting the residents from the states members of the European Union and on avoiding double international taxing. The specialized international organisms reached to the conclusion that the optimal solution for avoiding double taxing is represented by concluding bilateral or multilateral conventions between states, their disposals having the role to clarify the status of the residents involved in different economical activities in other states We present below the approached problems together with the new changes in force starting with January 1st 2009.