Pseudamnicola Paulucci, 1878 is a circum-Mediterranean genus which contributes substantially to hydrobiid diversity. In Turkey, the genus Pseudamnicola is mainly found in the southern regions. Material collected from an upper branch of Esen Stream in southwestern Anatolia yielded a new species, Pseudamnicola thalesi sp. n. The characters of the shell, head and male genitalia are described and illustrated. The new species is compared with those of its congeners that have been recorded previously in Turkey.