Species of the genus Mimastra Baly, 1865 (Coleoptera: Chrysomelidae) with discoid (M. oblonga group) and trapezoid (M. tarsalis group) protarsomere in males are revised. Mimastra oblonga group comprises 7 valid species: M. oblonga (Gyllenhal, 1808) comb. nov.; M. cyanura (Hope, 1831); M. lunata (Kollar & Redtenbacher, 1844); M. soreli Baly, 1878; M. latimana Allard, 1889; M. guerryi Laboissière, 1929 and M. anicka sp. nov. (Thailand and Myanmar); while M. tarsalis group includes only one species—M. tarsalis Medvedev, 2009. The primary types of almost all relevant taxa were examined. Galleruca oblonga Gyllenhal, 1808, listed for many years in the genus Aulacophora, is transferred to Mimastra. Status restored for four species (M. lunata, M. soreli, M. latimana and M. guerryi), often listed as synonyms of M. cyanura. Mimastra apicalis Baly, 1886 is a new junior synonym of M. lunata (Mimastra apicalis Baly syn. nov.) and M. quadrivittata Mader, 1938 is confirmed as a synonym of M. guerryi. Lectotypes are designated for Galleruca oblonga, Mimastra cyanura, M. lunata, M. apicalis and M. soreli. The syntype series of M. soreli consists of a mixture of two species. Its identity is fixed for the species from Sichuan. The second part of the syntype series refers to M. oblonga. Male protarsus, protibia and male and female genitalia of all the species are illustrated and key to the species is given.