The green-rumped parrotlet occurs from northern Venezuela eastwards to the lower Amazon in Brazil, Also Suriname and has been introduced to Curaçao, Jamaica and Barbados.

The green-rumped parrotlet was formally described in 1758 by the Swedish naturalist Carl Linnaeus in the tenth edition of his Systema Naturae.

[2] Linnaeus specified the type location as "America", but this was changed to Surinam by Hans von Berlepsch in 1908.

[3][4] The green-rumped parrotlet is now one of nine species placed in the genus Forpus that was introduced in 1858 by the German zoologist Friedrich Boie.

Green-rumped parrotlets exhibit sexual dimorphism: males have purplish-blue primaries, secondaries, and coverts, with bright turquoise feathers on the leading edges of their wings; females lack blue but have more yellow-green on the head.

[8] The male of subspecies F. p. cyanophanes has more extensive purple-blue markings that form an obvious patch on the closed wing.

The male of F. p. cyanochlorus has darker purple-blue markings than the nominate species; the female is brighter yellow-green.

[11] Green-rumped parrotlets are fairly common in open, semi-arid habitat and are found residing in dry scrubland, deciduous woodland, gallery forest, farmland, forest edges, and deforested areas throughout their range.

[15] Green-rumped parrotlets form strong pair bonds and rarely switch mates, but typically only breed with the same individual for 1–2 seasons.

Research has been done on resource allocation between different chick sizes by green-rumped parrotlet parents.

[20] It has been observed that over the course of mating and raising a brood of chicks, a female green-rumped parrotlet's mass varies greatly.

It is believed that this mass change is caused by a combination of brooding starvation, adaptation to a new lifestyle, and sexual activity.

[21] Green-rumped parrotlets primarily eat seeds from grasses and forbs, as well as flowers, buds, berries, and fruits.