State-owned enterprises (SOEs) have always been an issue for national legislators. Their regulation is conflicted between liberalization on the one hand and the need for public affairs to have more stringent rules on the other. Despite this difficulty, however, SOEs play an important role in the market, especially in key public services (thanks to which States are able to retain control of a sizeable part of their domestic economy). This paper examines the problems relating to the regulation of SOEs, especially considering that good governance of SOEs is critical to ensuring a positive contribution to the efficiency and competitiveness of national and international economies. Moreover, when the State plays the role of market regulator and competitor in a domestic market, it is essential to guarantee fair competition and a level playing field between the SOEs and private enterprises.