Systematics of the trilobite subfamily Koneprusiinae Vaněk and Pek, 1987 are revised on the basis of new material and a comprehensive parsimony analysis. New taxa include the genus Nevadaprusia (type species N. cortezensis n. sp.) from the Pragian of Nevada and the species Laethoprusia graffhami n. sp. from the Lochkovian of Oklahoma, L. cozarti n. sp. from the Lochkovian of Tennessee, and Laethoprusia n. sp. A from the Sheinwoodian of Arctic Canada and the southern Mackenzie Mountains. Nevadaprusia insolita (Haas) is revised on the basis of new material. Laethoprusia and Nevadaprusia are interpreted as sister taxa, and Koneprusia and Isoprusia are successive sister groups to the Laethoprusia/Nevadaprusia clade.