This diploma thesis deals with the taxation of Austrian self-serving external private foundations as defined by PSG with foreign beneficiaries. At first an overview of the establishment, dissolution and the main characteristics of a private foundation was given. In addition to an overview of the general taxation the focus of this work is on the one hand on the specially for private foundations existing interim taxation which triggered by an ECJ ruling out of 2015 was amended by the AbgÄG 2015. Because of this ECJ ruling on the other hand, the compatibility of the new rules with the free movement of capital has been tested. The question of the European legal compatibility of the interim taxation - in particular interim tax relief and interim tax credit - derives from the condition that donations of a private foundation must not be relieved from the withholding tax by a DBA, for the interim tax relief or interim tax credit to be eligible. Despite qualifying this condition as a restriction on the free movement of capital by the ECJ, it persists in the form as amended by the 2015 AbgÄG. Therefore, an examination of the new rules on the basis of free movement of capital appeared as necessary. After all, the new legal situation for Austrian private foundations created not necessarily legal certainty. Finally, an attempt was made because of these reasons to give a future view of the legal situation.