The legal discipline of social services occupies a central position with regard to the transformations that have affected and continue to affect national welfare systems in Europe. Indeed, while at the national level, sub-national authorities continue to play a significant role in providing these services, at the supranational level, a gradual «infiltration» of EU antitrust law has taken place. Nevertheless, this «infiltration», which only affects organizational aspects that are related to social services, does not appear capable of undermining the «social sovereignty» of Member States, which is established by Article106(2) TFEU and by some sectoral measures. Nevertheless, it could be important to begin a harmonization process in this field at the European level, to encourage virtuous reforms in the Member States and, thus, reduce the inefficiencies and inequalities that still characterize several national welfare systems.