A new species, Sclerocardius lyali sp. nov., is described and illustrated from Mae Hong Son Province, Thailand. The new species is close to Sclerocardius indicus Hartmann, 1903, but differs in the body covered with short setiform yellowish and pale scales, the postero-ventral side of the protibia lacking teeth, a pronotum with quite large punctation, and a narrower aedeagus. This is the first record of Sclerocardius Schoenherr, 1847, from Thailand. A key to Asian species of the genus Sclerocardi