The Grey-headed Warbler is described as endemic to northeastern Venezuela's mountains. A 1990s field paper recorded birds feeding in dense forest undergrowth and used an older genus name.
A juvenile observed near Cerro Negro had a uniformly dark-gray hood and upper breast, a brownish body, and paler underparts. Pale legs, loose feathers, a short tail, and a yellow gape suggested that it had fledged recently.
In 1993–1994, adults were seen in dense cloud-forest undergrowth and at forest edges, feeding low in foliage and sometimes moving with mixed-species flocks. The authors inferred breeding in about May–July and fledging in August.
An extinction-risk assessment has not been added yet.