From 1993 to 1997, we observed Scarlet Macaw (Ara macao) feeding behavior in Central Pacific Costa Rica. Feeding data acquired in this study were not collected systematically, but opportunistically whenever macaws were observed feeding. To supplement feeding observations, we conducted interviews with local residents. Scarlet Macaws fed on seeds, fruits, leaves, flowers and/or bark of 43 plant species. Various plant parts eaten by macaws from several tree species contain secondary compounds toxic to humans, and additional species included in their diet are nonnative, introduced for agricultural purposes. Important macaw feeding tree species are Ceiba pentandra, Schizolobium parahybum, and Hura crepitans; these species are also crucial to this macaw population because of nest cavities they provide. The results of this study contribute to the conservation of Scarlet Macaws in Central Pacific Costa Rica through promoting protection of individual trees, and through local elementary school reforestation programs focusing on tree species that macaws use for feeding and/or nesting. Scarlet Macaw conservation is extremely important, as numerous population pressures have caused significant declines in macaw numbers in Costa Rica.