A systematic revision of the species of the genus Xylocopa subgenus Neoxylocopa in Argentina is provided. Seven species are included: X. atamisquensis Lucia & Abrahamovich, X. augusti Lepeletier, X. eximia Pérez, X. frontalis (Olivier), X. mendozana Enderlein, X. nigrocincta Smith and X. tacanensis Moure. The males of X. eximia and X. nigrocincta are described for the first time. Xylocopa jujuyensis Brèthes is a new junior synonym of X. nigrocincta. Photographs, occurrence maps, and identification keys for the species are presented. Information on the nest architecture and substratum preference are also given.