Black cockatoos in southwest Western Australia face population declines as a result of habitat loss and fragmentation, poaching, competition with other species, vehicle strikes, and shootings. In this study, hematologic and plasma biochemical reference values were determined for 3 endemic Western Australian black cockatoo species: Carnaby's cockatoo (Calyptorhynchus latirostris) (n = 34), Baudin's cockatoo (Calyptorhynchus baudinii) (n = 22), and forest red-tailed black cockatoo (Calyptorhynchus banksii naso) (n = 22). Significant sex-related differences were detected in Carnaby's cockatoos, and differences were also found among the 3 species. The forest red-tailed black cockatoos showed a markedly greater eosinophil count than did the 2 white-tailed species. Blood values from samples obtained by different collection methods differed significantly for Carnaby's cockatoos, which indicates that anesthesia may affect analyte values and that collection methods should remain consistent. The results of this study will be useful for clinically evaluating wild black cockatoos that are undergoing rehabilitation for release and will provide baseline data for future investigations of free-living black cockatoo health.