The Chestnut-breasted Coronet is a mountain hummingbird with a green head and back and chestnut underparts. It feeds from the forest understory into the canopy.
The head and back are green, and the underparts are chestnut. The tail is beige with a dark terminal band. Females are slightly duller than males.
It feeds from the subcanopy into the canopy of montane forest.
An extinction-risk assessment has not been added yet.