It is a species of hummingbird in the family Trochilidae and the order Apodiforme, it measures around 8 cm.

They occur in humid forest, woodland and shrub at altitudes of 1000 to 4800 m in the Andes of Argentina, Bolivia, Ecuador, Colombia Peru and Venezuela, he’s threatened with habitat loss.

The feathering around its legs is black, which is unique among the puffleg. Otherwise its plumage is green with contrastingly black tail.

Black- thighed puffleg are active, territorial hummingbird that primarily feed on nectar from low flowers.