The Tropical Screech-Owl primarily preys on large arthropods and small vertebrates. There are few quantitative studies of the diet; Motta-Junior (2002) found, at three nests in Brazil, that vertebrates made up 34% of the biomass of prey consumed, and invertebrates the remaining 66%.
Documented vertebrate prey include small frogs (Hylidae), small snakes (including Helmitihophis), birds, opossums (Gracilinanus), bats, and small rodents (Bolomys, Calomys, and Oligoryzomys, Oryzomys) (Thomas 1977, Stiles and Skutch 1989, Motta-Junior 2002, Hilty 2003).
Invertebrates found in the diets include earthworms, scorpions, spiders, harvestmen, and a wide variety of insects, including roaches (Blattidae), termites (Termitidae), grasshoppes (Acrididae), katydids (Tettigoniidae), raspy crickets (Gryllacrididae), crickets (Gryllidae), mole cricketts (Gryllotalpidae), mantids (Mantidae), beetles (Coleoptera: Scarabaeidae, Cerambycidae), moths and caterpillars (Lepidoptera), and ants (Formicidae) (Thomas 1977, Haverschmidt and Mees 1994, Motta-Junior 2002). Motta-Junior reported that half of the biomass of invertebrates in his sample were of terrestrial gryllacridids, suggesting that the Tropical Screech-Owl frequently captures prey on the ground.