– Cyanallagma nigrinuchale (Sel.) and Oxyagrion brevistigma Sel. are recorded for the first time from Argentina, and Hetaerina rosea Sel. from Uruguay. New Argentinian records of H. rosea Sel., H. sanguinea Sel. and Castoraeschna decurvata Dunkle & Cook, and some corrective notes on the previously published lists are also provided.