This review of the New World subgenus Melanoconion of Culex includes taxonomic history, previous schemes of internal classification, revised subgeneric characters, summaries of bionomics, medical importance and distribution, discussions of included species, diagnostic features for separating Melanoconion from other related subgenera of Culex, its affinities and phylogenetic relationships. The taxonomic characters used are discussed and figured, followed by a detailed outline of the proposed scheme of internal classification, keys to sections, groups and /or subgroups and definitions of sections. A conspectus of taxonomic changes, including 2 transferred taxa, 10 provisionally rejected names and 5 new synonyms, is appended. Based on the study of types and /or available topotypic material, the male genitalia of 6 valid species are figured: phlabistus, saramaccensis, creole, pifanoi, idottus and ernsti.