The present invention provides a process for purifying 2-chloro-5-chloromethyl-1,3-thiazole represented by the formula (I): ##STR00001## characterized in that a crude 2-chloro-5-chloromethyl-1,3-thiazole represented by the formula (I) is treated with a lower alcohol before the distillation, and then is distilled. The present purification process is a new one for purifying 2-chloro-5-chloromethyl-1,3-thiazole, suitable for industrial practice.