It is generally a solitary and quiet bird unless it is breeding season, when the male and female become a monogamous pair and create a cavity nest in an old tree.

During breeding season both sexes share brooding and feeding duties for 25–30 days until the chick is ready to fledge.

The golden-headed quetzal, also known by the Spanish name pilco real,[1][2] was first described by John Gould in the 2nd edition of A Monograph of the Trogonidae or family of Trogons published in 1875.

Like other members of the genus Pharomachrus, the golden-headed quetzal is known for its iridescent golden-green wings and breast, which can appear blue depending on the light.

Their bills are short and broad; they appear yellow in males and a brownish greyish in females.

The quetzal's uppertail coverts are darker green and extend beyond the tip of the tail, more so in the male than in the female.

The young golden-headed quetzal is a brownish black colour with a few iridescent green feathers on the neck and breast, and lacking the tail coverts of the adult.

[11][12] When it does vocalize, its far-carrying call is very distinctive, sounding like mournful, hawk-like whistles, repeated 6-8 times ("whe-wheeu, whe-wheuu, whe-wheeu…").

[4] All birds in the family Trogonidae appear to be very responsive to recordings of their calls, which could indicate that their vocalizations are a territorial behaviour.

[13] The quetzal's fruit-heavy diet makes it a very important species for the dispersal of the fruits’ seeds.

Their observations also confirmed that the formerly accepted idea that quetzals did not feed their hatchlings fruit until ten days after hatching was untrue.

Quetzals form shallow, more open, unlined cavities from which part of the bird (head or tail) is usually visible.

While brooding, the adults enter the nest to feed the nestling; when brooding ends, the adults initially continue to enter the nest but spend less time inside before leaving; at 8 days before fledging they simply lean in to feed the chick before departing; finally at 4–6 days before fledging the chick is able to perch on the lip of the nest and is fed from there before the adult departs.