They have white lores and supercilium, an olive line through the eye, and whitish ear coverts with faint darker speckles.

Their throat is whitish and their underparts yellow with faint olive streaks on the breast and sides.

[5][6][7] The greenish tyrannulet is found in southern Brazil in an area roughly bounded by southern Mato Grosso do Sul, Espírito Santo, and central Rio Grande do Sul, in southeastern Paraguay, and in Misiones and northern Corrientes provinces in northeastern Argentina.

[5] The greenish tyrannulet's breeding season has not been fully defined but includes October and November.

Its nest is purse-like with a side entrance, made of moss, and suspended from a branch low to the ground.

[1] It is considered uncommon in most of its range; it does occur in protected areas in all three countries it inhabits.

It is "[a]pparently not entirely dependent on undisturbed forest; found also in secondary vegetation and edge habitat".