Adult females have olive-brown upperparts with a grayish tinge on the crown and nape and yellowish brown uppertail coverts.

It forages singly, in pairs, or in family groups, and often as part of a mixed-species feeding flock.

It actively, but methodically, seeks prey especially among vine tangles and also from leaves both live and dead, stems, and branches, mostly by reaching and stabbing.

The nest is a cup made from roots, dead leaves, and fungal fibers hung from a branch fork, typically within about 2 m (7 ft) of the ground.

The clutch size, incubation period, time to fledging, and details of parental care are not known.

The unicolored antwren's song is an "irregular series of very high, sharp, drawn-out, well-separated 'Seeep' notes".

"Virtually all lowland Atlantic forest outside protected areas has been deforested within its historical range for human encroachment, logging and conversion for agricultural purposes."

"More survey work is needed in order to assess the distribution and population levels of present species in [the southern] portions of its range".