Thermotherapy using natural thermal mud has played a crucial role for human health care since ancient times. However, recently the SPA and Wellness Centers have come into prominence with the exhaustion of primary reserves of natural thermal mud. In these centers, instead of natural thermal mud, peloids prepared using clay and/or clay minerals with thermal or mineral water through maturation process that changes the physicochemical properties of the clay and/or clay minerals. Turkey has several clay reserves / however, the investigation about their suitability for the pelotherapic applications is not adequate. The aim of this study is to investigate the mineralogical, chemical, and physicochemical properties of the 13 different samples collected from K&uuml / &ccedil / &uuml / khacibey, Hancili, and Kazbekir localities in &Ccedil / ankiri and Kizil&ouml / ren, Karadirek, and H&uuml / dai localities in Afyonkarahisar in order to evaluate their suitability for pelotherapic applications. The results of mineralogical, chemical, and physicochemical analyses including cation exchange capacity, swelling index, plastic index, water loss, specific surface area, grain size and cooling rate properties were compared with the results in the previous studies. For maturation process distilled water and two different commercial mineral water with different chemical compositions were used. At the end of the four week long maturation, the peloids are evaluated in the sense of consistency, ease of handling and pleasant sensation during application. Evaluation of analyses results showed that clay deposits in Hancili and K&uuml / &ccedil / &uuml / khacibey localities in &Ccedil / ankiri can be considered being suitable for pelotherapic applications. On the other hand, clay deposits in Kazbekir locality in &Ccedil / ankiri and in all three localities in Afyonkarahisar cannot be considered being suitable for pelotherapic purposes.