The Brown-headed Greenlet is distributed in the region of the upper rio Negro covering north-west Brazil, southern Venezuela and south-east Colombia. It seems to be restricted to sandy-soil forest in blackwater areas.

It has a brownish crown and nape with a greyish underparts. It looks very similar to Dusky-capped Greenlet H. hypoxanthus but that species has pale yellow underparts. The bill is dark above and pinkish-yellow below. The eye colour is a bit confusing since Hilty in "Birds of Venezuela" says "eyes gray to whitish (or reddish brown in juv.?)" while in "Birds of Colombia" he says, "eyes dark".