The paper presents the concept of disposal of cooled geothermal brines by re-use in borehole salt mines where they are further saturated with sodium chloride. The target recipients of the brines – saturated to reach industrial brine requirements - would be chemical plants. Currently mines produce industrial-quality brine with surface water. Using model options of cooperation of geothermal plants (hypothetical one in Mogilno and one in construction in Toruń) with salt mines (Przyjma and Góra), it is shown that the payback period for major capital expenditures (drilling, pipeline) would be of 10-15 years. The solution would provide tangible benefits for geothermal plants (elimination of costs associated with implementation and maintenance of reinjection wells). Strategic advantages for salt mines would be extending the lifespan of the salt deposit. As there is no need anymore for re-injection of heat-depleted brine, implementation of the solution also enables simpler – in technological terms – production of thermal waters with high level of mineralization. Assessment of geothermal potential in the area of these mines indicates that to achieve maximum energy performance and ecological benefits, it would be advisable to supply the mines with waters with mineralization of >100gNaCl/L from the Lower Jurassic aquifer in the area of the Mogilno Trough. The geothermal plants could operate in parallel in several towns and, assuming they would be supplying enough brine to fully meet the mines’ demand (1000-1100 m3/h) and the temperature of obtained waters would be >80°C, the total production capacity of these geothermal installations could reach 80-100 MW.