The Central and East European countries (CEEC) have many common features. All of them were strongly influenced by centrally managed economic system in socialism period (1947-1989). Characteristic for this period was utilization of cheap energy sources imported almost exclusively from the former Soviet Union, extremely high industrial energy intensity, low level of energy efficiency, over-consumption of natural resources as well as high stage of environmental pollution. The following period (since 1990) has been characteristic of a difficult process of transition from a central planned system to a market economy, accompanied by a process of de-monopolization and privatization, liberalization of trade and capital flows, development of financial markets and process of decentralisation of public administration. Coessential were also crucial reforms in health-care system, judiciary, school and pension systems and tax reforms. Despite a traumatism of the overall process, the outcomes have been very positive - such as liberalisation of the economy, attraction of foreign direct investments and increasing the quality of life. In this period, even the very first ideas related to energy savings, energy efficiency and RES utilization have been taken into accounts and consequently presented to the leading decision makers at the national level. However, there had not been sufficient incentives to accept and further develop these ideas to concrete activities till 2000. The bigger progress has been evident since the beginning of 21st century, and especially, after the accession of some of the CEE countries to the European Union (the Czech Republic and Slovakia acceded on 1st May 2004 and Bulgaria and Romania on 1st January 2007). The specific goal of this Master Thesis is to describe and compare the situation in two groups of CEE countries: Czech Republic / Slovakia and Bulgaria / Romania in relation to utilization of renewable energy sources (RES). The pivotal topic of this Master Thesis was chosen after receiving an approval from the Supervisor Mr. Roman Doubrava, director of the Energy Centre Bratislava (ECB), as well as experts from the Raiffeisen Bank, Raiffeisen Leasing GmbH and Raiffeisen Energy & Environment GmbH / REE.