The Nile Valley Sunbird has a striking breeding male with bright plumage and a long forked tail. Females and non-breeding males are duller.
A breeding male has a greenish head, blue-violet back, yellow underparts, and a long forked tail. Females are duller, and non-breeding males have shorter tails and resemble females.
It feeds mainly on nectar and also takes small arthropods. In its described range, bright breeding males occur alongside duller plumages outside the breeding season.
An extinction-risk assessment has not been added yet.