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, heโ€™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.