A systematic study of the chewing louse genus Lagopoecus (Phthiraptera: Ischnocera: Philopteridae) was undertaken to identify several species found among the undetermined specimens in the K. C. Emerson Collection at Oklahoma State University. This paper treats the species found on pheasants and their relatives (Galliformes: Phasianidae: Phasianinae). The known species are redescribed and illustrated, the male of L. choui Liu and the female of L. ovatus (Uchida) for the first time. One species (L. colchicus Emerson) is probably a synonym of L. sinensis (Sugimoto).