A powerful predator, its diet consist mainly of small mammals, rodents, snakes and smaller birds.

The tail is fairly long, measuring 34 to 43 cm (13 to 17 in) in length, in part accounting for the considerably low weights cited for an eagle of this size.

Forest-dwelling raptors often have a relatively small wingspan in order to enable movement within the dense, twisted forest environments.

The distinctive juvenile crested eagle is white on the head and chest, with a marbled-gray coloration on the back and wings.

This species often overlaps in range with the less scarce Harpy eagle, which is likely its close relative and is somewhat similar to appearance.

[5] It is sparsely distributed throughout its extensive range from northern Guatemala through Belize, Honduras, Nicaragua, Costa Rica, Panama,[5] the subtropical Andes of Colombia, northeastern Venezuela, Guyana, Suriname, French Guiana, Brazil (where it has suffered greatly from habitat destruction,[6] being now found practically only in the Amazonian basin[7]), and east Andean Ecuador, southeastern Peru, Paraguay and eastern Bolivia to north Argentina.

The crested eagle lives in humid lowland forests, mostly comprised by old growth tropical rainforests.

[2][8] The crested eagle seems to be a still-hunter, as it has been observed perched for long periods of time while visual scanning the forest around them.

[11] Other mammalian prey may include numerous arboreal rodents as well as opossums, sloths and kinkajous.

[14][15] In Tikal, the primary prey appeared to be opossums, from tiny mouse opossums to mid-sized Didelphis species, and the largely nocturnally-active prey of crested eagles indicated a deeply searching hunting technique, which overlapped with the black hawk-eagle in the region but not with the region's ornate hawk-eagle, which, in spite of its smaller size, tended to take larger prey and be more opportunistic as well as having a stronger predilection for bird-hunting.

[16] Various studies have also pointed to the abundance of snakes (both arboreal and terrestrial varieties with several instances of predation on boas reported) and other reptiles (principally lizards including iguanas) in its prey base, but the relative frequency of different types of prey apparently varies greatly on the individual level and reptiles appear to take a secondary position to mammals.

[2] The clutch size appears to be typically two but only one eaglet has ever been known to hatch from crested eagle nests.

Tropical forests such as the Amazon are so heavily degraded and logged that they are thought to be unable to sustainably support most forest-dwelling raptors native to them.

[23][24] The crested eagle is believed to no longer occur in several former breeding areas where extensive forest have been cleared.