Heat supply industry is one of the economic energy industries. The heating supply companies are considered local monopolies. This state is caused by customers having practically no opportunities to change the supplier or the way of heating. The reason for this is mainly the investment intensity of obtaining the technology of heating systems. The specific problem concerning the heating supply companies lies in the fact that the majority of customers are households which, as a result of increasing prices of consumed thermal energy, are interested in savings. The volume of heat sales to households depends particularly on outside temperature. The customers cannot be motivated to make higher purchases because they take only as much thermal energy as they need to balance heat losses of a heated object. The dissertation thesis called 'The marketing behaviour of a heating supply company in a regulated energy industry' deals with the possibilities of using marketing tools in companies that are active in price-regulated energy industry. It outlines the basic relationships that individual subjects in the heat supply industry establish among themselves and it analyses these relationships. First and foremost it contains the assessment of influence of external factors on heating supply companies. It points out the possibilities of using individual elements of the marketing mix in a heating supply company, a combination of elements or specific conditions in heat supply industry of only one of them. The cause of this state is seen in the fact that the product is unambiguously determined, the price is significantly regulated by state represented by the Energy Regulatory Office and the system for thermal energy distribution is firmly established. It is shown that pointed and effective use of the marketing communication tools (especially the creation of public relations, sales and advertising support) is the most effective element of the marketing mix. While preparing the dissertation thesis, individual hypotheses were determined and established facts were confronted with real conditions in a specific heating supply company, VYTEZA, s.r.o., which supplies heating to more than 3700 households in the city of Vyškov.