This paper presents a thorough review and a complete amalgamation, with some modification, of the internal classification of the genus Anopheles. Both formal and informal taxa are included. The classification is intended to aid researchers and students who are interested in analysing species relationships, making group comparisons and testing phylogenetic hypotheses. The genus includes 458 formally named and provisionally designated species divided among six subgenera. The largest subgenera, Anopheles, Cellia and Nyssorhynchus, are further divided into various descending informal groupings down to species level. These groupings include Sections, Series, Groups, Subgroups and Complexes. Other terms applied by some authors to levels of classification represented by these categories have been changed in order to establish a degree of uniformity in the application of informal group names within the genus. A few changes involving groups and species assignments have been made to eliminate duplicity or clarify concepts.