The scintillant hummingbird is only 6.5–8 cm (2.6–3.1 in) long, including the bill and is one of the smallest birds in existence, marginally larger than the bee hummingbird.
The unique orange throat of the male, distinguishes it from all other hummingbirds.
The female scintillant hummingbird is entirely responsible for nest building and incubation. She lays two white eggs with incubation taking 15 to19 days, and fledging another 20 to 26 days.