The North American genus Gnathium of the meloid subfamily Nemognathinae is reviewed. Adults appear to be confined to inflorescences of Asteraceae. The genus includes 11 species primarily distributed in western and southern United States and northern Mexico. Included is a discussion of the taxonomic status of the genus, a review of known biology, a key to species, and descriptions. Species treatments include host data, and details on seasonal and geographic distribution, and intraspecific variation. Two new species are described and three nominal species are placed in synonymy.