EN
World species of the genus Acinaces are reviewed, keyed and illustrated. The following new synonyms are proposed: Acinaces lebasii Gerstaecker, 1858 (=Acinaces curtus Pic, 1938); Acinaces laceratus Gerstaecker, 1858 (=Acinaces laceratus junctus Pic, 1938). The lectotypes are designated for Acinaces lebasii Gerstaecker and Acinaces laceratus Gerstaecker. Four new species: Acinaces gerstaeckeri (Colombia), A. pakaluki Bolivia), A. unicolor (Brazil), A. ovatus (Brazil, Venezuela, Paraguay) and one subspecies Acinaces lebasii stroheckeri (Bolivia, Brazil) are described. Distribution, nomenclatural history and diagnoses are provided for each species.