Iron deficiency anemia is a human health problem of global significance, particularly as it affects pregnant women and infants. While the study of nonhuman primates has resulted in valuable knowledge about iron metabolism, hematologic and biochemical reference ranges for the parameters of iron metabolism are difficult to document in healthy monkeys. At our institution, we maintain a large breeding colony of healthy cynomolgus monkeys (Macaca fascicularis). Data compiled after sampling nonpregnant females and male members of this colony are presented as reference ranges for red cell number, hemoglobin, hematocrit, mean cellular volume, mean cellular hemoglobin, mean cellular hemoglobin concentration, serum iron, total iron-binding capacity, serum transferrin, and serum ferritin.