Tariffs for energy and energy resources are the main factors determining the sustainable development of the economy. The aim of the paper is to determine and compare the dynamics evolution of the tariffs for thermal energy and the evolution of the gross domestic product (GDP).The data on the heat consumption and tariff change in the city of Chisinau were examined in monetary terms and in relative units compared to the base year 2009. The higher the tariffs, the more part of the GDP, characterized in the economy by the volume of "Output", is spent on "Intermediate consumption (PP)". The difference between "Output" and "Intermediate consumption" volumes is the "gross added value (VAB)", which is the main component of GDP. The analysis of the changes in the real GDP volume of the Republic of Moldova and the increase of the tariffs for the years 2009-2017 (taking into account the GDP forecast for 2018) show that the increase in the tariffs for thermal energy significantly exceeded the real GDP growth. Considering that the planned GDP growth is 4,7% and taking into account the change in the consumer price index (inflation rate), the calculated reduction of the thermal energy tariff in Chisinau is estimated at 28% compared to the existing value, so to 803 lei / Gcal compared to the currently regulated value of 1122 lei / Gcal. The conclusion was reached on the opportunity of applying the proposed methodology to justify current tariffs and in the near future not only extends to thermal energy tariffs, but also for other types of energy, material resources and services in the field of production and social sphere.