Guyana toucanets are frugivorous, with a diet primarily composed of fruit. They occasionally consume insects for protein.

Their long, light beaks help them reach food in places where other birds cannot. Their bill allows them to access fruit on branches that might not be able to support their weight. Toucanets engage in bill-fencing and wrestling, most likely to establish hierarchy within a group. They release excess body heat through their beaks, similar to other toucan species.

Their main predators are arboreal carnivores such as birds of prey, snakes, and occasionally jaguars.

Courtship involves ritual throwing of fruit to each other, and nesting occurs high up in hollowed trees. Their bills are not effective for extensive excavation work, so they rely on pre-existing holes. They lay 2 to 4 eggs, with the female doing most of the incubation. After 16 days, blind nestlings are born with no trace of down on their pink skin. Both parents share in feeding fruit to the young. The young fledge at around 40 to 42 days old. The bill starts to develop distinguishing features of a toucan at around 16 days old and takes up to four months to fully develop.

They have a lifespan of approximately 20 years.

The Guyana Toucanet is classified as Least Concern on the IUCN Red List. Although their population is currently stable, the loss of suitable habitat due to deforestation is expected to cause a decline in their numbers.