Since the time of the Roman Empire, thermal water has been known for curative effects, becoming more and more used for relaxation, recreation, medical purposes, in the form of aerosols with very good results for local and international patients suffering from a series of affections, especially rheumatic diseases and chronic inflammatory diseases of the skin. All available scientific data are presented regarding the thermal springs in Romania, located in the north-western area of the country, an area with a geological structure for a better understanding of the biological mechanism of action of these waters in terms of composition, physico-chemical properties and its clinical benefits for patients. Seven thermal springs from Romania were analyzed for chemical compositions. Most of the springs release water diluted to slightly saline with sodium bicarbonate, with a neutral to slightly alkaline pH, such as Băile Calacea (Timiș county), Băile Herculane (Caraș-Severin county), Băile Lipova (Arad county), Băile Figa (Bistriţa-Năsăud county), Băile Acâș-Mihăieni (Satu Mare county), Băile Felix (Bihor county), Băile Tinca (Bihor county). Most springs are theoretically in thermodynamic equilibrium in relation to calcite and fluorite.