This special issue explores recent case law and elaborates on the interplay between public procurement and State aid. The two fields of law share the common aim to ensure that competition is undistorted on the internal market. As regards State aid rules, TFEU contains a prohibition that excludes Member States from granting any kind of aid to an undertaking, which might place other undertakings at an unjustified competitive disadvantage. The objective of public procurement rules is to ensure that the competition for public contracts remains free and open ; when a contracting authority awards a certain contract, it does so on the basis of either the lowest price or the most advantageous economic offer and irrespective of the nationality of the tenderer. Without these rules Member States would not be constrained in funding beneficial companies ; either by granting favourable contracts to companies or through unrestricted subsidy.