The diversity of two subfamilies of cuckoo wasps in northeastern Brazil is reviewed. Four new species are described and illustrated:Amisega boyiLucena,sp. nov.,A. sertanejaLucena,sp. nov., andDuckeia duduiLucena,sp. nov.(Amiseginae), andCleptidea nordestinaLucena,sp. nov.(Cleptinae). These new species ofAmisegaandDuckeiarepresent the first records of both genera in the core zone of the Caatinga dry region, and they seem to be endemic to this portion of the region. The other twoAmisegaspecies previously recorded in northeastern Brazil are restricted to ecotone habitats between Caatinga and Atlantic forest.Cleptidea nordestinaLucena,sp. nov.(Cleptinae) is the most septentrional record for thefasciataspecies group in South America. With the present contribution, the total recorded diversity of Amiseginae and Cleptinae in northeastern Brazil is represented by the following species:A. boyiLucena,sp. nov.,A. flavipesKimsey, 1987,A. sertanejaLucena,sp. nov.,A. similisKimsey, 1987, andD. duduiLucena,sp. nov.(Amiseginae), andC. nordestinaLucena,sp. nov.(Cleptinae).