The haemoproteids of the avian passeriform families Fringillidae and Emberizidae s.l. are reviewed. In the Fringillidae, Haemoproteus fringillae of the Fringillinae is redescribed from the type host; within the Carduelinae, H. chloris is redescribed from the type host, and four species, H. globulosus, H. macropigmentatus, H. serini, and H. tartakovskyi, are synonymized with it. In the Emberizidae s.l. Haemoproteus quiscalus is redescribed from the type material, H. mazzai of the Cardinalinae is redescribed, and H. hedymelis is synonymized with it; H. coatneyi of the Emberizinae, H. paruli of the Parulinae, H. coereba of the Coerebinae, and H. thraupi of the Thraupinae are described as new species. A single taxon is recognized from each subfamily, and specificity at the subfamilial level is the primary taxonomic characteristic. The haemoproteid species involved are pleomorphic and are morphologically similar to one another.