Halotherapy or speleotherapy in salt mines refers to treatment by stay in salt caves. The main therapeutic indication concerns respiratory diseases (chronic obstructive pulmonary disease (Copd), asthma). The beneficial effects were discovered empirically in 1843 by Felix Bochkowsky in the Wieliczka Salt Mine. Treatment centers have been structured in different countries of Eastern Europe, Germany, Austria, Turkey and Russia. Because of the unique characteristics of each mine and the variety of treatment programs, speleotherapy is considered as a class of intervention. Artificial salt chambers were created in the 80s. Speleotherapy is considered as a complementary care for the treatment of respiratory diseases in different European countries. Since 1969, the Romanian speleotherapy association organizes international scientific conferences. The main curative factor consists in an aerosol of sodium chloride and oligoelements coming from the convective erosion of the walls of the mine. The inhalation of hypertonic saline aerosol induces hyperosmolar stimulation, increases mucociliary clearance, has a bactericidal effect and reduces bronchial inflammation. Salt and moisture increase the fluidity of the bronchial mucosa and improve its rheology. The beneficial effects of speleotherapy in Copd, asthma and the breathing performance of athletes were highlighted. There is a need of randomized controlled clinical trials with long-term follow-up. The creation of health resorts in salt mines represents virtuous model of environmental reconversion of industrial sites.