There are about 30 species in the cockroach genus Allacta Saussure & Zehntner. Several species are redescribed, or the previously unknown sex is described, and the literature for all the known taxa is given, including original author's descriptions if specimens were not available. Two new species, namely, fascia and loconti are described. Allacta basivittata (Bruijning), previously a junior synonym of Allacta bipunctata (Walker), is considered to be distinct. Allacta montaguei Chopard is transferred to Balta Tepper. Allacta raapi Hanitsch is transferred to Sundablatta Hebard. Allacta variegata (Brunner) is placed in Margattea Shelford. Allacta crassivenosa (Bolívar) is retained incertae sedis. The species are placed in 3 groups and a key is presented to distinguish the adults.