An identification table and descriptions are given to recognize the two species of Hypodynerus ( Hymenoptera: Vespidae: Eumeninae) recorded from Brazil: Hypodynerus arechavaletae (Brèthes) and Hypodynerus duckei (Bertoni) comb. n. The lectotype is designated and the male is described for Hypodynerus duckei , its presence being recorded from Brazil for the first time.