The forest green tree frog, Zhangixalus arboreus, is a Rhacophorid species naturally distributed in Honshu and Sado Islands from Japan. This species is also known to have been introduced to the Izu-Oshima Island. In this study, we examined the feeding habits of Z. arboreus in Izu-Oshima Island because the knowledge of its foraging strategies may contribute to addressing conservation efforts on the island. We observed that frog stomachs contained 65 animal prey items, exclusively arthropods belonging to classes Arachnida, Insecta, and Diplopoda. The frog stomachs contained terrestrial and arboreal arthropods, suggesting that Z. arboreus feeds in a variety of habitats. We also found a large number of ants in frog stomachs. Our results differ from a previous study carried out on native populations of this species, which may be indicative of habitat differences among populations.