This study reviews theDicharaxspecies in Thailand. Altogether tenDicharaxspecies are reported, four of which are new to science and described herein. They areDicharax borealisJirapatrasilp & Páll-Gergelysp. nov.,Dicharax burchiJirapatrasilp & Páll-Gergelysp. nov.,Dicharax panhaiJirapatrasilp & Páll-Gergelysp. nov.andDicharax pongratiJirapatrasilp & Tongkerdsp. nov.Alycaeus davisiGodwin-Austen, 1914 is regarded as a junior subjective synonym ofAlycaeus cucullatusTheobald, 1870 (=D. cucullatus) based on a similar depressed-conical shell shape, a long sutural tube and a sharp swelling behind the peristome. Furthermore, the type locality ofAlycaeus pratatensisPanha & Burch, 1997 (=D. pratatensis) had to be amended. Most important characters to distinguishDicharaxspecies are the general shell shape and relative lengths of teleoconch regions, whereas the spiral striation of R1, the shape of swelling of R3, the outer peristome crenulation and protrusion, and the exterior opercular sculpture show large intraspecific variability.