It is found in Brazil, Colombia, Ecuador, French Guiana, Guyana, Peru, Suriname, and Venezuela.

[8][9][10] Males of subspecies M. l. subplumbeus have underparts almost as dark as their upperparts and smaller white tips on their wing coverts than the nominate.

[8][9][10][11][12][13][excessive citations] The subspecies of the spot-winged antbird are found thus:[8][9][10][11][12][13][excessive citations] Some sources add extreme northwestern Bolivia to the range of intensus[1][8][9] but the South American Classification Committee of the American Ornithological Society has no records from that country[14].

The spot-winged antbird primarily inhabits the floor and understorey of terra firme evergreen forest.

[8] The spot-winged antbird's diet has not been detailed but is known to be mostly insects and arachnids and also include small lizards.

It forages as individuals, pairs, and small family groups and mostly within about 1 m (3 ft) of the ground and only rarely with mixed-species feeding flocks.

[8][9][11][12][excessive citations] The spot-winged antbird's breeding season has not been fully defined but apparently includes October in French Guiana, January in Brazil, and February in Venezuela.

Subspecies M. l. intensus of the spot-winged antbird sings "a rapid, fairly even-paced series of ringing notes: pi’i’i’i’i’i’I’I’I’i’i’i’i’i’i’i’i".

[8][12] The species' calls include a "long, downslurred, typically frequency-modulated whistle", an "abrupt unclear note given singly or in series of 2–5", and a "short rattle".