A taxonomic treatment of the adults of the 12 known species of Neoleucopis Malloch, a subgenus of Leucopis Meigen, whose larvae prey on Adelgidae, is presented. The genotype, N. pinicola Malloch from North America, and two European species, N. atratula (Ratzeburg) and N. obscure Haliday, are redescribed; a neotype is designated for the former species and a lectotype is selected for the latter one. N. tapiae Blanchard, described from Argentina but known from many parts of the world, and N. manii Tanasijtshuk from India, are also redescribed. Seven new species are described: aciliosa (Japan), ancilla (Oregon), freyi (Switzerland, Finland), militia (Pakistan), nigraluna (India), orbiseta (Finland), and setigera (Chile). The paper includes a key to adults, and 40 figures.