Introduction. The fact itself that thermo-mineral waters and mud have healing effects has always attracted attention throughout the history to exploit, explore and study their benefit on the human body. Modern lifestyle and the speed of life endanger man’s psycho-physical health. This is why people more often return to old time proven values, the nature and natural health resorts. Objective. To establish hydro-geological conditions for the formation of mineral water and to summarize their balneological characteristics in spas, i.e., in rehabilitation centres of the Pannonian basin of the Republic of Serbia, where underground waters are still actively exploited for balneotherapy. Methods. By retrospective descriptive analysis, a recapitulation of hydro-geological conditions for the formation of mineral waters was made and their balneological characteristics were established in eight spas of the Pannonian basin. Results. The healing spas of the Pannonian basin are predominated by HCO3 (2.9 g/l - 4.6% milival), iodic (up to 6.5 mg/l), slightly alkaline (pH up to 8.1) thermal-mineral water (temperature up to 72°C, bounty to 36.6 l/s) with a significant content of Br (up to 8.1 mg/l), Fe (to 6.0 mg/l), metaboron (up to 60 mg/l) and metasilicon acid (up to 95 mg/l). They are used for external application, bathing and showering. Conclusion. Once the Pannonian Sea (the Paratethys), today a wide plain terrain is a tectonic depression of the lower Pannonian pont age with compact type aquifers. In the geological column of sedimentary rocks a large underground aquifer was formed with free water of high mineralization, high temperature and geothermal properties above the average in relation to the European hydrogeological standards. Therefore, the Pannonian basin can be rightly called a thermal valley with the predominance of sodium hydro-carbonate (alkaline) iodine healing water of enviable abundance and reserves.