The Crimson-rumped Toucanet's plumage is mostly green, frequently tingued blue. The rump and tail tip are maroon-red. The beak is black and maroon, with a white band at its base. The average length is 14 inches (35 cm) - from the top of the head to the tip of the tail. The weight ranges from 5 - 8.2 oz (141-232 grams). They are fairly long-lived with a lifespan around 20 years.

Usually seen in pairs or small flocks of eight or so. These noisy, active birds cover a lot of area when looking for food in the mid to canopy levels of the forest. Diet consists primarily of fruits. They also eat insects for protein during the breeding season. Occasionally they feed on small animals, eggs, lizards, etc. Water is mainly from fruits, however, they have been seen drinking from bromeliads.

The mating ritual is a fun-loving affair for toucans, as they throw fruit to one another. Like all of their other activities, nesting happens high up in hollow areas in trees. The bill is not effective for digging or any other type of extensive excavation work and so they must rely on holes already formed by other means.

The nests are not lined, but the two to four shiny white eggs that are laid each year rest on a few wood chips created while enlarging the opening or on various kinds of regurgitated seeds collected for this purpose. Parents share equally in incubation duties, but rarely sit on the nest for more than an hour at a time and the eggs are often left uncovered. Both parents share in feeding fruit to the babies for up to 8 weeks.

After 16 days the nestlings are born blind, with no trace of down on their pink skin. The bill is unremarkable until about 16 days old when it takes on the distinguishing features of the toucan, and requires up to four months to develop fully. Feathers begin to expand at 4 weeks. Babies have pads on their elbows that protect their feet by keeping them elevated until they fledge. Breeding in captivity requires attention to a number of details. Even successful breeders report rates as low as 30% for the incubation of eggs.

Nests are high up in hollow areas usually in rotted wood and unused woodpecker holes. Even though the bill is long, it is not effective for digging – they must rely on old nest holes. They can enlarge the opening if needed and the wood shavings are at the bottom of the nests, on which two to four shiny, white eggs are laid. The nestlings hatch after 16 or 17 days, with both parents feeding fruit to the babies for up to eight weeks. They are blind and naked at birth, with feathers developing at four weeks. They fledge at approximately 40 days.