Oleoresin extracted from copaíba (Copaifera spp.: Leguminosae) trees is a popular traditional medicine in Amazônia. I studied production ecology from three copaíba types in the eastern Brazilian Amazon. Mean oleoresin yield from the first harvest was 0.07 liters per tree for all trees drilled and 0.23 liters per tree for ones yielding some oleoresin. Yields were comparable to C. multijuga results in central Amazônia but lower than anecdotal reports of 2 liters or more per tree. Yield differences were minor between tree types and seasons. Yield peaked in mid-size trees (45–65 cm DBH) while small (<45 cm DBH), very large (>65 cm DBH), and hollow trees (due to senescence or fire) yielded negligible amounts. Oleoresin was harvested almost exclusively from inner heartwood, indicating that factors stimulating its synthesis in cambium are probably distinct from factors that promote its storage in heartwood and loss of yield many years later.