Reference intervals for clinical chemistry analytes are important for the interpretation of blood results, but reference intervals available in journal articles for specific flamingo collections are often based on a small number of individuals or are only available for a limited number of analytes. Differences in husbandry and nutritional conditions may impact reference intervals. The goal of this study was to establish reference intervals from a mixed population of greater (Phoenicopterus roseus) and American (Phoenicopterus ruber) flamingos when husbandry parameters are equal and to compare the results between the different species, sexes, and age groups in order to evaluate differences between these factors. Lithium-heparinized plasma samples from 93 animals were analyzed for the following: amylase, cholinesterase (CHE), bile acids (BA), total protein (TP), glutamate dehydrogenase (GLDH), aspartate aminotransferase (AST), creatine kinase (CK), lactate dehydrogenase (LDH), uric acid (UA), inorganic phosphorus (P), total calcium (Ca), sodium (Na), and potassium (K). The results show many differences between the species and a few between the different age groups but no differences between males and females of either species. Amylase (P= 0.0010), AST (P= 0.0090), CK (P= 0.0011), and Ca (P= 0.0217) differed significantly between greater and American flamingos. The age group significantly impacted blood levels of CK (P = 0.0299) and LDH (P = 0.0165) in greater flamingos and BA (P = 0.0495), P (P = 0.0422), and Ca (P = 0.0006) in American flamingos. The results show the importance of species-specific reference intervals and the consideration of age-related variations in order to facilitate correct interpretation of blood results.