Scissor-tailed Nightjar occurs in South America, east of the Andes, from eastern Peru (locally, north to southwestern Loreto and Junín) south to eastern Bolivia, Uruguay, Paraguay, and central Argentina (south to Mendoza), and east to northeastern Brazil. There also is an isolated population on the Sipalwini savanna, Suriname, where it is believed to breed (Haverschmidt and Mees 1994, Ottema et al. 2009). Scissor-tailed Nightjar is assumed to be resident in most of its range, but is described as migratory in the southern portion of its range (Short 1975); the extent of migration in this species, however, is not well documented. Apparently largely disappears from Rio Grande do Sul, southern Brazil, in the southern winter, but even there some may remain year round (Belton 1984). Apparently Scissor-tailed Nightjar is resident in Andean foothills in Peru, but it is suspected to be only an austral migrant at lower elevations in southeastern Peru (Schulenberg et al. 2010). Hennessey et al. (2003) suggest that Scissor-tailed Nightjar may be an austral migrant to Bolivia.
Generally the elevational range of Scissor-tailed Nightjar is from the lowlands up to 1100 m (Parker et al. 1996), but in Peru it occurs locally up to 1700 m (Schulenberg et al. 2010), and even to 2700 m in Bolivia (Hennessey et al. 2003).