The White-tailed Goldenthroat has metallic green upperparts and a white-tipped tail. In eastern Colombia it uses savannas, grasslands, and forest edges, feeding on nectar and sometimes hovering at flowers.
The male is green throughout, with glittering green underparts. The female is greenish above and greyish-green below. The tail is mostly greenish with large white tips.
It feeds on nectar from flowering plants, reaching into flowers with its long bill. It may also eat small insects and spiders, and can hover while feeding.
The male has a white stripe above the eye; the female has white stripes above and below it.
The bill is reddish and black, and curves gently downward.
An extinction-risk assessment has not been added yet.