The Nearctic species of subfamily Porricondylinae are revised, based mainly on an examination of the Felt types. The history and the classification of the tribes and genera here recognized as constituting this subfamily are reviewed, and the subfamily is redescribed to include these groups. The systematic position of every described Nearctic species within this subfamily is reviewed, and most of the species are redescribed. Porricondyla varians is described as new. Keys are included to tribes, genera, and species. The subfamily is divided into 8 tribes, one of which, the Heteropezini, contains genera which have hitherto been referred to other subfamilies. These tribes are further divided into 27 genera (Colpadia is considered not to occur in the Nearctic) of which PSEUDOCAMPTOMYIA, NEOSYNEPIDOSIS, ISOCOLPODIA, PARACOLPODIA, and BASICONDYLA are described as new. Eight genera previously recognized only in Europe have been added to the Nearctic lists, and 2 previous synonyms (Hormosomyia and Rübsaamenia) have been maintained. These genera include 85 species; there are in addition 2 species which are not referred to any genus, to make a total of 87 valid species for the subfamily. In this revision, 25 new synonyms are established between Nearctic species, 2 Nearctic species are synonymized under a European species, 1 European species is synonymized under a Nearctic species, several tentative synonyms are suggested, and 44 new combinations are established.