The Scrub Nightjar is an aerial insectivore. Very little detailed information on the diet; beetles (Scarabeidae, subfamily Dynastini, tribe Cyclocephalini; unidentified beetles), moths, and grasshoppers were found in the stomachs of several specimens (Robbins et al. 1994). Foraging occurs primarily in flight or from sallying from a branch to capture insects when it is most active at dusk and evening hours.
Aerial foraging occurs in open grassy and arid barren areas, wet pastures and areas with scattered bushes, light woodlands and edges of deciduous woodlands (Robbins et al. 1994, Cleere 1998, Ridgely and Greenfield 2001a, Ridgely and Greenfield 2001b).
Foraging microhabitats include areas above bush tops and concentration on feeding at particularly favorable sites (Robbins et al. 1994, Ridgely and Greenfield 2001b).
The order of Caprimulgiformes, which include the Scrub Nightjar have particularly well-developed cecae (DeGolier et al. 1999). It is believed that the presence of cecae is involved in the digestion of the hard exoskeleton containing chitin from its insectivorous diet (DeGolier et al. 1999).