The genus Neolophonotus is discussed. A brief history of work on this huge genus is given, and the methods adopted in the present study are stated. A key to six newly proposed species-groups is provided, viz. angustibarbus, chionthrix, comatus, pellitus, squamosus and suillus groups. Three of these groups are dealt with, and 38 new species descriptionbed. New species in chionthrix group: acuminatus, agrestis, actites, amplus, anguicolis, coetzeei, crassicolis, crenulatus, expandocolis, leucothrix, macrocercus, milleri, namaqua, namibiensis, obtectocolis, robertsoni. New species in squamosus group: ausensis, bicuspis, brevicauda, lawrencei, nigriseta, schalki, spinicaudata, squamosus, stevensoni, theroni, truncatus. New species in angustibarbus group: culinarius, gertrudae, junodi, kalahari, rolandi, schoemani, swaensis, torridus, trilobius, zimbabwe, zulu. New synonyms: Antilophonotus Lindner, 1955 (=Neolophonotus Engel, 1925); N. rhodesiensis Hobby, 1933 (= N. rapax (Ricardo, 1920)). New status: The subspecies N. molitor chionthrix Hull, 1967 is raised to full specific status. New combinations: Lophonotus albibarbis Macquart, 1846 is transferred to Neomochtherus; Dasypogon scapularis Macquart, 1838 is transferred to Gonioscelis. Keywords: Afrotropical Asilidae, Angustibarbus, Asilinae, Asilini, Chionthrix, Squamosus, Diptera, Neolophonotus and Robber flies.