We assessed diet from a sample of Jackson's chameleons inhabiting wet forest in Volcano Village, Hawai‘i Island, Hawai‘i. Most lizards contained food in their gastrointestinal tract, diet was broad, and large numbers of invertebrates, mostly insects, were consumed. Native insects composed the largest component of dietary items, and these spanned most of the body-size range found in the native invertebrate community. Taxonomic composition of diets does not conform to expectations for iguanian lizards inasmuch as hymenopterans form only a small portion of consumed items. Insect chemical or stinging defenses did not preclude consumption by lizards. The study site is a mixture of native and alien vegetation. Chameleons collected from alien plants contained larger numbers of native prey items than did those lizards removed from native plants, suggesting that lizard residency on non-native plants will not reduce their predation impact on native invertebrates in mixed forest. Our results confirm the finding of a similar study in dry-forest habitat on Maui that Jackson's chameleons are likely to pose a substantial threat to a broad range of native invertebrate biodiversity in Hawai‘i.