The neotropical palm swift is a slender, narrow-winged species, 13.2 cm long, with a long forked tail, and weighs 11 g. The call is a buzzed djjjjjj, like an insect. The nominate western form T. s. squamata has black-brown upperparts with a slight greenish gloss. The underparts are a paler brown with a white throat and central underbody. The eastern race T. s. semota of Trinidad, the Guianas and central and eastern Brazil is much darker, almost steel-black above and darker brown below. Juveniles are very similar, but have buff fringes to the upperparts and head in fresh plumage.
It feeds in low flight on flying insects. It normally stays at less than 10 m above the ground. It normally occurs in small groups of up to 30 birds.
This small bird is found locally in marshy habitats, or sometimes open forest, usually near Moriche Palms. It builds a C-shaped nest of feathers, saliva and plant material on the inside of the dead leaf of a Moriche Palm. Three white eggs are laid in the depression of the C, and incubated for 21 days to hatching.