Abstract The new genus Notocoderus and the new species N. argentinus are described from Buenos Aires Province, Argentina, based on two specimens taken in pitfall traps. Dorsal and lateral digital images of this new subbrachypterous oxycarenid and Dycoderus picturatus Uhler, known only from Arizona and Colorado in the United States, are provided and their relationships with each other and other oxycarenids are discussed. A lectotype for D. picturatus is designated.