Three subspecies often recognized, although König and Weick (2008) consider the species to be monotypic:
oberholseri, described as Glaucidium minutissimum oberholseri Moore 1937; type locality Vado Hondo, central Sinaloa, Mexico
Occurs in Sonora and Sinaloa.
Similar to nominate palmarum, but "darker above, pileum Olive Brown compared with Saccardo's Umber, tail Clove Brown compared with Bister, middle of back Olive Brown compared with Sepia, flanks more solid brown and much darker, Bister as compared with Snuff Brown; light streaks of under parts pure white instead of buffy white; large area of white on throat, whereas none in Type of palmarum; bristles on toes white instead of buff; wing and tail shorter, culmen longer" (Moore 1937: 105).
palmarum, described as Glaucidium palmarum Nelson 1901; type locality Arroyo de Juan Sánchez, Nayarit, Mexico
Occurs from Nayarit to Oaxaca.
See Detailed Description.
griscomi, described as Glaucidium minutissimum griscomi; type locality El Rancho Protero de los Indios, 12 miles south of Zirandaro, Guerrero, Mexico
Occurs in the Rio Balsas Valley in Guerrero and Morelos, Mexico.
"Nearest in the gray phase to the same phase of Glaucidium minutissimum oberholseri Moore ... but differieng in having (1) back and scapulars much grayer; (2) wing-coverts and primaries paler; (3) spots on pileum and region posterior to auricular area more numerous; (4) nuchal color [= collar?] across upper back not so prominently marked with white; (5) upper tail coverts paler brown (paler than the dark portion of middle rectrices, instead of the same color as in oberholseri); (6) size larger, 11% in the taik; (7) white spots on three outer rectrices averaging larger. It differs in the same way from the gray phase of ... palmarum ... except for size, but to a far greater extent, all of the brown areas both above and below being very much grayer (duller brown) as compared with the rusty brown color of these areas in palmarum" (Moore 1947: 33).