Resumo. ABSTRACTThis study aimed to report the registration of new ant species in Rio Grande do Sul state and thus tocontribute to the knowledge about the ant fauna (Myrmecofauna). Collections were made in four differentenvironments, namely, native forest, eucalyptus plantations, agricultural plantation and exotic pasture. Weused the mini-Winkler method of extraction to collect the ants. We removed 1 square meter (1m²) of litter,sifted it and packed it in mini-Winkler extractors to obtain the fauna. We collected 108 species, whichrepresent 31 genera, 18 tribes and 8 subfamilies. The native forest presented 90 collected species, theeucalyptus plantation presented 65 species, and the agricultural plantation and the exotic pasture presented20 species each. We have registered for the first time the following species in the state of Rio Grande do Sul:Dorymyrmexthoracicus (Dolichoderinae), Camponotus arboreus,Camponotusmelanoticus(Formicinae), Apterostigma madidiense,Apterostigmasp.pilosumcomplex, Cyphomyrmexmajor, Cyphomyrmexvorticis, Wasmannia rochai, Cephalotes pusillus,Strumigenys (Pyramica)rugithorax, Strumigenyscosmotela, Strumigenyssilvestrii,Pheidole aper,Pheidoleheyeri,Pheidolerugatula,Pheidole siggilata,Pheidolesenilis,Pheidolesospes,Megalomyrmex pusillus (Myrmicinae), and Pachycondyla ferruginea(Ponerinae).