Semiaquatic bugs (Hemiptera, Heteroptera, Gerromorpha) are small to mid-sized insects, currently represented by more than 2,100 known species distributed on all continents, except Antarctica. So far, 244 species have been recorded from Brazil, but only 63 from the Northeast Region of the country. The relatively small number of species in this region is related to the virtual lack of knowledge on the fauna of the Caatinga, a biome that is distributed essentially throughout this region. We present here new records for 28 species based on material collected in four federal conservation units of the Caatinga biome: Aiuaba Ecological Station (Ceará state), Chapada Diamantina National Park (Bahia state), Catimbau National Park (Pernambuco state), and Serra das Confusões National Park (Piauí state). Moreover, several species are recorded for the first time from at least one of these states: 11 from Bahia, 10 from Ceará, two from Pernambuco, and eight from Piauí.