There are rich reserves of underground mineral waters in the south of Tyumen region, which are generally deep located, in the so-called difficult exchange water zone (on average at a depth of 1311.29±34.53 m). Currently, there is a lack of assessment of prognostic resources of underground mineral waters in the south of Tyumen region. The article provides an assessment of underground mineral (therapeutic) waters’ reserves (2011—2019 yrs.) in the considered territory. It was shown that the number of deposits, their sites and underground mineral waters’ well bores is 76, of which less than half are in operation, as at date of 01.07.2021. Moreover, the number of deposits is remained almost constant since 2011 yr. Meanwhile, underground mineral (therapeutic) waters’ reserves are gradually decreasing. Thus, there is a necessity to intensify not only the stocktaking and identification of mineral waters’ well bores, but also to develop the new medical technologies to use geothermal waters in rehabilitation and prevention. Monitoring for underground waters’ condition should be continued with the use of modern research tools and techniques. The above mentioned will give a new impetus to the development of health resort sphere in the tourism industry, in addition to increasing the therapeutic effects of mineral waters.