The Purple-throated Woodstar bears some resemblance to the White-bellied Woodstar, even though they do not belong to the same genus. Their flying behavior is more like a bee, in that they move swiftly and without sharp turns like most hummingbirds do. As they fly over, they do sound like bees. They are also pretty small, like most woodstars. It does not have the glittering green body of the White-bellied; instead, the back is a duller green color, and the belly is olive with orange feathers covering the legs and white vent. A white ring almost surrounds completely the neck. The female has a white-gray throat, while the male has an iridescent purple throat (as the name would suggest) that looks rather dark from some angles.

The female of this species has a whiter and duller throat, it does not glow purple with light.

Depending on the angle, the throat may look almost black, but a slight movement can change its color to metallic purple.

In this pose, looking almost directly to the camera, the purple throat is clearly visible. Also the white neck ring is feature.

This is a very small hummingbird. It does have a long tail.