The revision of the American species of Carebara Westwood is offered. This study recognized one genus and 31 species (20 described as new) from United States to Argentina as follow: Carebara Westwood, 1840 (= Oligomyrmex Mayr, 1867 syn. nov.; = Aeromyrma Forel, 1891 syn. nov.; = Aneleus Emery, 1900 syn. nov.; = Erebomyrma Wheeler, 1903 syn. nov.; = Paedalgus Forel, 1911 syn. nov.; = Lecanomyrma Forel, 1913 syn. nov.; = Spelaeomyrmex Wheeler, 1922 syn. nov.; = Hendecatella Wheeler, 1927 syn. nov.; = Solenops Karawajew, 1930 syn. nov.; = Sporocleptes Arnold, 1948 syn. nov.; = Crateropsis Patrizi, 1948 syn. nov.; = Nimbamyrma Bernard, 1953 syn. nov.; = Afroxyidris Belshaw & Bolton, 1994 syn. nov. (provisional); = Neoblepharidatta Sheela & Narendran, 1997 syn. nov). The following species complexes and species are recognized and proposed: Carebara concinna SPECIES COMPLEX: C. longii (Wheeler) comb. nov. (USA); C. peruviana (Emery) comb. nov. (Peru); C. urichi (Wheeler) comb. nov. (Mexico to Brazil) [= Erebomyrma nevermanni Mann syn. nov.; = Erebomyrma morai (Menozzi) syn. nov.; = Erebomyrma eidmanni Menozzi syn. nov.; = Erebomyrma urichi (Wheeler); = Oligomyrmex nevermanni (Mann); = O. morai (Menozzi); = O. eidmanni (Menozzi)] and C. brevipilosa sp. nov. (Costa Rica to Brazil). Carebara lignata SPECIES COMPLEX: C. anophthalma (Emery) (Brazil, Ecuador, Guyana) [= C. winifredae Wheeler syn. nov.]; C. bicarinata Santschi (French Guiana); C. bruchi (Santschi) comb. nov. (Argentina); C. coeca sp. nov. (Brazil, Colombia); C. elongata sp. nov. (Colombia); C. globularia sp. nov. (Colombia); C. incierta n.n. (Brazil); C. longiceps (Santschi) comb. nov. (Argentina); C. mayri (Forel) (Paraguay); C. minuta sp. nov. (Brazil); C. panamensis (Wheeler) comb. nov. (Panama); C. reticulata sp. nov. (Colombia); C. stenoptera (Kusnezov) comb. nov. (Argentina); C. tenua sp. nov. (Brazil). Carebara escherichi SPECIES COMPLEX: C. angulata sp. nov. (Colombia, Ecuador); C. audita sp. nov. (Colombia); C. brasiliana sp. nov. (Brazil); C. inca sp. nov. (Peru); C. intermedia sp. nov. (Belice); C. kofana sp. nov. (Colombia); C. majeri sp. nov. (Brazil); C. nuda sp. nov. Brazil; C. paya sp. nov. (Colombia); C. pilosa sp. nov. (Brazil); C. reina sp. nov. (Colombia); C. striata sp. nov. (Colombia, Brazil, Peru) and C. semistriata sp. nov. (Colombia). The following combinations are proposed for the Old World species of Paedalgus: Carebara distincta (Bolton & Belshaw) comb. nov., Carebara escherichi (Forel) comb. nov., Carebara infima (Santschi) comb. nov., Carebara octata (Bolton & Belshaw) comb. nov., Carebara pisinna (Bolton & Belshaw) comb. nov., Carebara rara (Bolton & Belshaw) comb. nov., Carebara robertsoni (Bolton & Belshaw) comb. nov., Carebara sarita (Bolton & Belshaw) comb. nov., Carebara sudanensis (Bolton & Belshaw) comb. nov. and Carebara termitolestes (Wheeler) comb. nov. The definive knowledge of the taxonomy of Carebara needs to await more complete series, including female, male and especially major with minor workers (in the dimorphic species). C. minuta would be one of the smallest ant species of the World with a head width of 0.21 mm and total length slightly below 1 mm.
