The systematics of the lycaenid genus Hypochrysops C. & R. Felder is revised. Descriptions are given of previously unknown sexes of some species and of seven new taxa: Hypochrysops luteus sp.n. (Irian Jaya and Papua New Guinea), H. castaneus sp.n. (Papua New Guinea), H. miskini parvulus ssp.n. (Papua New Guinea), H. ferrugineus sp.n. (New Britain), H. geminatus sp.n. (Irian Jaya and Papua New Guinea), H. hippuris nebulosis ssp.n. (Queensland and Papua New Guinea), and H. theoncretatus ssp.n. (Queensland). Twenty-eight names of species level are placed in new synonymy. Keys to the genera of the Hypochrysops section of the Luciini (sensu Eliot 1973) and to the species of Hypochrysops are presented. The male genitalia of all available species are described and figured. The genus now revised includes 57 species for which 20 species-groups are proposed. Waigeum Staudinger is considered to be a synonym of Hypochrysops. The distribution and aspects of the biology of the species are discussed.