There is little information on the breeding of Dusky Hummingbird, apart from the observations by Rowley (1984). Breding is reported from March, May, August, November, and December (Rowley 1984, Howell and Webb 1995). The nest is a small cup, placed in 1.2-2 m above the ground in a shrub (n =3; Rowley 1984). The nest is composed of "plant fibers, lined with soft plant down and a few feathers", with the exterior of the cup "heavily covered with dead leaves, grass stems, and small pieces of bark, giving it the appearance of being a naturally formed accumulation of debris" (Rowley 1984). Nest dimensions are total depth, 47.2 mm; external diameter, 55.0 mm; diameter of cup, 30.0 mm; and depth of cup, 25.7 mm (n = 1; Rowley 1984). One set of eggs measured 12.5 x 8.3 mm and 12.7 x 8.6 mm (Rowley 1984). There is information on the length of the incubation or nestling periods.