The article discusses a relation in between energy security and state ownership of the enterprises active in energy and fuel sector. A history of privatisation efforts carried out both in Western Europe and in post-communist countries is presented to give background for current state of the governmental involvement in the sector. The main part of the article is devoted to individual analysis of selected countries representing various models of ownership policy, among others: USA, UK, Germany and Russia. These analysis are complemented by a chapter discussing the issue of competition between so called National Oil Companies, owned, or at least controlled by governments and Global Oil Companies, public but almost purely privately owned ones. They indicate a variety of ownership models applied or rather developed due to differences in size and structure of natural energy resources, balance of internal supply and demand, military strength, political position, particular model of free market economy in general, membership in key international organisations. All the factors mentioned have lead to a situation in which a total lack of governmental ownership in the sector’s corporation can be attributed only to USA and UK. In all other countries analysed states act as important or even dominant shareholders in key energy companies, trying to pursue, in more or less open ways, their policies. Having understood that their results depend very much on the strength and international presence of state controlled corporations governments promote their business development through adoption of the most advanced managerial practices, research in technology and participation in global cooperation with key players in energy and energy related sectors. Therefore they do not exclude neither a partial participation of private investors nor bringing state controlled companies to, even foreign, stock exchanges. But always governments execute control over activities related to energy security and protect these corporations from hostile takeovers. On the other side governments actively support the controlled companies on various fields for example trying to weaken certain EU regulations, negotiating international agreements considering their presence abroad or granting licences for their own natural resources on preferential terms. In conclusion it is stated that no universal “correct” or “European” pattern regarding neither state ownership in energy companies nor using this tool for protecting energy security exists. Therefore Poland has to select solutions most adequate to it’s own situation and apply them in the most effective way.