An annotated checklist of the Chrysididae from Mongolia is provided. A revision of the bibliographical data is provied, since most of the collecting localities published for “Mongolia” refer to places currently located in China. The known Mongolian cuckoo wasp fauna counts 90 species in 18 genera and two subfamilies. Four genera and 57 species are recorded for the first time, including two species here described as new for science: Cleptes mongolicus Rosa, Halada & Agnoli, sp. nov. (Dornod) and Spinolia spinosa Rosa & Halada, sp. nov. (Bayankhongor).