The species diversity and higher level classification of Ptychopteridae (Insecta: Diptera) is examined with cladistic methods using morphological and molecular datasets. The taxonomic status of Ptychoptera contaminata Linnaeus is discussed, and a neotype designation is proposed. The Afrotropical fauna is detailed as part of a larger reference work of Diptera in the region. The structure and homologies of male genitalia within the family are examined, and a new standardized terminology is proposed, supported with colorized illustrations. An illustrated key is provided for the Nearctic species of both subfamilies. The extant species of the subfamily Bittacomorphinae are revised, including redescriptions, illustrations, and a key. The extant species of Ptychopterinae are revised in a similar manner, and the subgeneric structure of the genus is reassessed in the first comprehensive classification of the taxon. In total four new species are described from North America and one from eastern Asia, and five new subgenera are erected.