The Tetramorium solidum-group occurs in Africa, with the vast majority of species endemic to the arid regions of southern Africa. In the more than 30 years since the first revision of the genus by Bolton (1980), ant surveys have considerably expanded the amount of material available, including surveys conducted specifically for this study. This review, based on both morphological and genetic data, has expanded the number of known species from 14 (Bolton 1980) to 19, constituting an increase of 36%. Keywords: Tetramorium solidum-group, Afrotropical region, arid regions, Nama Karoo, Succulent Karoo, new species, rainfall.