Little information. Chilensis breeds November-January in Chile, where Johnson (1967) believed that two broods usually are raised per season. Subspecies modesta is found on the breeding grounds November-June (Zimmer 1941, Schulenberg et al. 2007), but within this period, nesting probably takes place from December-January or February. The breeding seasons of the non-migratory subspecies (griseogularis, diversa, urubambae, albiceps) have not been documented.
The nest of chilensis is a small cup of plant fibers (grasses, leaves, lichens or mosses) and small twigs, with a lining of feathers or thistle-down (Johnson 1967). The nest is placed in the fork of a shrub or tree. Also, one nest was reported from a cavity (Ojeda and Trejo 2002); this is the only cavity nest reported for the genus Elaenia. The clutch is two-three eggs. The eggs are creamy-white, with a few red spots. Johnson (1967) gives dimensions of the eggs as 20.0 ± 0.24 mm x 14.9 ± 0.05 mm; the sample size for these measurements was not given. The incubation and fledging periods are not known.