Two dermestid beetle species, Th. mentawaiana sp.n. from Siberut Island of Indonesia and Th. sausai sp.n. from Laos and Thailand, both belonging to Thaumaglossa hilleri species group, but differ by the structure of their antennae and male genitalia, are described, illustrated and compared with related species. Two species are also recorded in the region for the first time, namely Th. pacholatkoi Háva, 2015 for Java Island of Indonesia, and Th. panda Herrmann et Háva, 2015 for the Hubei province of China.