The present contribution addresses some questions related to the application of State Aid regime in the area of taxation, in particular in relation to the territorial restrictions contained in favorable tax measures adopted by Member States. In a first part, the definition of Regional Aid is precised, since this notion can have different meanings. In a second part, the issue of the compatibility of favorable tax measures limited to a part of a territory of one Member State is addressed. Finally, some comments are made on the coherence between the treatment in EU law (European Commission’s practice and caselaw of the European Court of Justice) of territorial tax advantages in the area of fiscal State aid and of fundamental freedoms to tax measures.