Two subspecies currently recognized:
cyanocephala, described as Ornismya cyanocephalus (Lesson 1829); type locality Brazil, but this obviously an error, probably from Veracruz, Mexico
Occurs from eastern Mexico south to central Guatemala. See Detailed Description.
Includes guatemalensis (descrided as Cyanomyia Guatimalensis Gould 1861), a subspecies of Guatemala, Belize, El Salvador, and western and central Honduras. This subspecies reportedly differs by having the "tail much brighter bronzy, the rump and upper tail-coverts also much more strongly glossed with bronzy" (Ridgway 1911: 427); but guatimalensis is only a "weakly differentiated subspecies" (Monroe 1968), and specimens from central Guatemala "show strong intergradation" with nominate cyanocephala (Weller 1999; see also Wetmore 1941). Also includes Amazilia microrhyncha (described as Cyanomyia microrhyncha Elliot 1876), which is a juvenile Azure-crowned Hummingbird (Phillips 1971).
chlorostephana, described as Amazilia cyanocephala chlorostephana Howell 1965; type locality 15 kilometers SSW of Waspam, Comarca de El Cabo, Nicaragua
Occurs in the lowlands of southeastern Honduras and northeastern Nicaragua.
Similar to nominate cyanocephala, "but with the crown glittering Green instead of Cobalts Ultramarine (blue); size smaller" (Howell 1965: 449).
Howell (1965) and Monroe (1968) considered it possible that chlorostephana represents a distinct species, but provisionally classified it as a subspecies of cyanocephala; Weller (1999: 598-599) reported that "nominate [cyanocephala] (in E of range) shows clinal variation in crown colour towards chlorostephana".