The author benefitted from the support of the private security sector as the Chief Officer of the City Police. When, after leaving the service, he was the President of the Polish Association of Employers Protection Branch “Małopolska”, one of the basic objectives of his activity was to ensure a high level of functioning of the private security sector as an important component of public security. Optimisation of the use of private security companies to ensure public security and order is one of the basic directions of his practical operation and research conducted by him. In the article, the author discusses the role of the private security sector and the tasks set for this sector. The genesis of security companies, their evolution and development in various countries of Europe and the world is covered. Much attention is devoted to the de-monopolisation of security in Poland, in which the security companies played a special role. The author outlines the most important objectives of private sector development in Poland as a specific type of economic activity. The basic concepts related to the functioning of security companies are explained, exposing their priority task, which is the protection of facilities, areas and equipment important for the functioning of the state. The author shows that the current level of terrorist threats implies the need for greater involvement of security companies in providing security to facilities constituting the critical infrastructure of the state. The role of specialist armed security formations in this area is highlighted. In the conducted research process, a positive answer to the main question is given, demonstrating that security companies are currently an important element of the public security system in Poland, and their use in this area should be constantly strengthened.