The systemic transformation in Poland, aimed, among others, at activating market mechanisms, has resulted in a change in the ownership structure and privatization that has accompanied it. Privatization processes are commonly considered to be principally motivated by an increase in efficiency of the economy based on the assumption that efficiency of private enterprises is higher than that of public sector ones. The main aim of the article is to verify the above hypothesis. An analysis of efficiency of public and private sector enterprises, taking into account their organizational and legal forms, made on the basis of Central Statistical Office information, confirmed the above hypothesis. Private enterprises use their assets better and take advantage of the financial leverage mechanism to a larger extent. It should be emphasized, however, that private enterprises are more adversely affected by economic fluctuations caused by the crisis.