Three new species of the giant pill-millipede family Zephroniidae are described from southern Vietnam: Sphaerobelum pumatense sp. nov., Sphaeropoeus honbaensis sp. nov. and Sphaeropoeus bidoupensis sp. nov. Two species, Sphaerobelum bicorne Attems, 1938 and Sphaeropoeus maculatus (Verhoeff, 1924), are redescribed, the former from new material, the latter from type material with lectotype designation. A new transfer is proposed: Zephronia manca Attems, 1936, to the genus Sphaeropoeus Brandt, 1833, giving the new combination, Sphaeropoeus manca (Attems, 1936) comb. nov.