Krynica is considered as one of the most famous and valued Polish health resorts, where curing waters are the fundamental treating material. Krynica's curing waters were described in historical sources far before their chemical constitution had been recognised. Balneological characteristics of Krynica's curative waters. All Krynica's waters are characterised by natural content of carbon dioxide, so can be ranked among oxalate. In their chemical constitution dominant anion is bicarbonate, whereas among positive ions are sodium ("Zubers") or sodium, magnesium and calcium in "Słotwinka" and "Mieczysław", calcium and magnesium in "Jan", eventually only calcium in "Tadeusz", "Józef" and "Zdrój Główny". These waters vary significantly according to the degree of general mineralisation from 0.06% ("Jan"), 0,12-0,45% ("Tadeusz", "Józef" and "Zdrój Główny") to 2,1-2,9% ("Zubers"). In waters belonging to the "Zuber" category can also be found certain curing elements like iodide, bromide and metaborate acid. In waters of the "Mieczysław" and "Słotwinka" considerable quantity of barium has been found . Occurrence and concentration of the elements mentioned above determine the pharmacological properties of Krynica's waters. Despite similar general influence, particular waters produce different effects, what has been proved by investigation and clinical observations carried out especially during applying "Jan", "Główny", "Słotwinka" and "Zuber" waters in drinking treatment. Krynica's curative waters can be divided into three main types: 2,1-2,9% bicarbonate-sodium, boron, bromide, iodide oxalate, ("Zuber") 0,16- 0,43% bicarbonate-calcium oxalate ("Tadeusz", "Zdrój Główny", "Józef") 0,11-0,88% bicarbonate-calcium-magnesium oxalate ("Słotwinka", "Mieczysław", ("Jan").