A review of the literature on Meloidogyne Goeldi, 1887 (endoparasitic gall-forming nematodes in roots of higher plants) emphasised the need for a detailed morphological study of the genus to provide an adequate basis for the identification of its species. The taxonomic study reported here confirmed the morphological distinctness of 23 species, including four new ones–M. decalineata sp. n., M. ethiopica sp. n. and M. megadora sp. n. from Africa and M. indica sp. n. from India. M. inornata Lordello, 1956a and M. tadshikistanica Kiryanova & Ivanova, 1965 may also be distinct species but M. poghossianae Kiryanova, 1963 is regarded as a species inquirenda. Meloidogyne spp. can be identified by the posterior cuticular pattern of the females and the morphology of the water-hatched, fixed larvae and of the males. Measurements, especially of water-hatched, fixed larvae are also useful in the differentiation of species. An improved technique for identification of Meloidogyne spp. is proposed and keys based on adults and on larvae are presented. Types are designated for M. exigua Goeldi, 1887, M. arenaria (Neal, 1889) Chitwood, 1949, M. hapla Chitwood, 1949, M. incognita (Kofoid & White, 1919) Chitwood, 1949, M. javanica (Treub, 1885) Chitwood, 1949 and M. thamesi Chitwood in Chitwood, Specht & Havis, 1952 (Goodey, T., 1963). The genus Hypsoperine Sledge & Golden, 1964 is rejected and two of its species renamed M. graminis (Sledge & Golden, 1964) comb. n. and M. spartinae (Rau & Fassuliotis, 1965) comb, n., while H. acronea (Coetzee, 1956) Sledge & Golden, 1964 is returned to M. acronea Coetzee, 1956.