RESUMO: Manonychus Moser, 1919 is a poorly known South American genus, predominantly occurring in Brazil. Recently, phylogeny confirmed its monophyly and placement in Sericoidini. The taxonomic revision of Manonychus is presented. Its species number increased from 8 to 34 species, out of which 24 are new species: Manonychus androgracilis sp. nov.; M. boraceiensis sp. nov.; M. bravoi sp. nov.; M. brunneoiridis sp. nov.; M. casariae sp. nov.; M. cleideae sp. nov.; M. cordiformis sp. nov.; M. cuiabanus sp. nov.; M. depressus sp. nov.; M. freyi sp. nov.; M. leticiae sp. nov.; M. maranhensis sp. nov.; M. massuttiae sp. nov.; M. mermudesisp. nov.; M. moronisp. nov.; M. morretensissp. nov.; M. moserisp. nov.; M. paschoali sp. nov.; M. planaltinaensis sp. nov.; M. sandyae sp. nov.; M. stanleei sp. nov.; M. veretrimonodentatus sp. nov.; M. veretrotruncatus sp. nov. and M. virbidentatus sp. nov. The following species formerly placed in Astaena Erichson, 1847 are here transferred to Manonychus: M. micans (Frey, 1973) comb. nov. and M. rotundiceps (Frey, 1973) comb. nov. Based on this study Manonychus is distributed in Brazil except the Amazon region, Bolivia and Paraguay. An identification key to species is presented along with illustrations, distributional data, and maps.