This paper presents the results of research into the energy and economic justification of gasification of the Split-Dalmatia County. Spatially distributed predictions of heat energy consumption by consumption sectors, in individual cities and settlements, a gas network model, an assessment of investment costs, and an assessment of the dynamics of natural gas penetration into the heat market in individual sectors are given. Based on this and the set economic acceptance criteria, the justification of investing in gasification of cities and settlements in the county has been determined.