Abstract The nephilid genus Nephilengys, known for its synanthropic habits, large webs with a retreat and the extreme sexual size dimorphism, is revised. Of the twenty-three available names, only four species with a globally allopatric distribution are recognized, illustrated and described from both sexes: N. cruentata (Fabricius, 1775) inhabits tropical Africa and South America, where it has probably been introduced; N. borbonica (Vinson, 1863) is found on Madagascar, Comoros, Seychelles and the Mascarene Islands; N. malabarensis (Walckenaer, 1842) ranges from India and Sri Lanka to China, Japan and eastern Indonesia; N. papuana Thorell, 1881 stat.n. is known from New Guinea and tropical Australia. Nephila instigans Butler, 1876 is the proposed syn.n. of N. borbonica; N. borbonica livida Vinson, 1863 is syn.n. of N. borbonica; N. niahensis Deeleman-Reinhold, 1989 is syn.n. of N. malabarensis; N. rainbowi Hogg, 1899 is syn.n. of N. papuana. N. kenmorei Barrion & Litsinger, 1995, here proposed as a nomen dubium, is an araneid. Nephilengys biology is reviewed and its anatomy summarized for use in a phylogenetic analysis of 197 characters scored for all Nephilengys, selected nephilid species and non-nephilid outgroups. Two new clades are circumscribed, the ‘cruentata species group’ (with N. cruentata and N. borbonica) and the ‘malabarensis species group’ (with N. malabarensis and N. papuana).