The Empis (Coptophlebia) hyalea-group is especially diversified in the Oriental region and is here partly reviewed. Twelve new species from Thailand are described and keyed, namely Empis (Coptophlebia) atratata sp. n., E. (C.) kosametensis sp. n., E. (C.) lamruensis sp. n., E. (C.) miranda sp. n., E. (C.) nahaeoensis sp. n., E. (C.) nganga sp. n., E. (C.) pakensis sp. n., E. (C.) pseudospinotibialis sp. n., E. (C.) pulchra sp. n., E. (C.) ratburiensis sp. n., E. (C.) spinotibialis and E. (C.) thapensis sp. n. The group is recorded for the first time from the Nearctic and Neotropical regions, and is presently known to be distributed in tropical and subtropical regions of Central America, Africa, Southeast Asia and Australasia, and Southwestern North America.