The infraorder Gerromorpha (Insecta, Hemiptera, Heteroptera) comprises semiaquatic bugs, most of which live on the water surface, among floating plants or at the margins of water bodies. We made collections of these insects in the Itapecuru and Parnaíba hydrographical basins in eastern Maranhão state, northeastern Brazil, from January to December 2019. Based on the material obtained, we present new records for 23 species, 20 of which are recorded for the first time from Maranhão state.
