This data publication contains information collected as part of a field and laboratory effort to determine prevalence of avian malaria (Plasmodium relictum) and pox-like lesions (Avipoxvirus spp.) in native and non-native forest birds on Molokaʻi in the Hawaiian Islands. Forest bird banding data, observations of pox-like lesions and blood samples for diagnosis of Plasmodium relictum, the agent responsible for avian malaria in the Hawaiian Islands, were collected in 2003 from wet and mesic habitats on eastern Molokaʻi, including Kalaupapa National Historical Park, Kamakou Preserve, Pelekunu Preserve and Puʻu Aliʻi Natural Area Reserve. These areas were the last locations where Olomaʻo (Myadestes lanaiensis rutha) and Iʻiwi (Drepanis coccinea) were observed in 1980 and 2010, respectively (Smith et al. 2025). Only two species of honeycreepers (Hawaiʻi ʻAmakihi, Chlorodrepanis virens and ʻApapane, Himatione sanguinea) still persist. These data report morphometric data, age, sex, molt status, pox virus-like (Avipoxvirus spp.) lesion occurrence, and diagnostic results for avian malaria from native and non-native forest birds that were captured with mist nets. This XML describes two tabular CSV files: Molokai Banding Table with Diagnostics.CSV and Standard Curve.CSV. The former file contains the analyzed data for Moloka’i, while the latter contains only calibration data Smith, L. K., S. W. Judge, A. S. Genz, L. Berry, L. K. Berthold, H. L. Mounce and R. J. Camp. 2025. Population trends of native and non-native forest birds on the island of Molokai'i, Hawai'i. The Wilson Journal of Ornithology, 137:51-64.