Perchlorate (ClO_4^-), an oxidizing agent, is a ubiquitous environmental pollutant. Several studies have investigated its thyroid hormone disrupting properties. Its associations with other biological measures are largely unknown. This study, combining 2005-2008 National Health and Nutrition Examination Surveys, investigated associations between urinary perchlorate and biomarkers of iron homeostasis, lipids, blood cell counts, and glucose metabolism. Healthy males (n = 3705), non-pregnant females (n = 2967), and pregnant females (n = 356), aged 12-59 years, were included in the linear regression models, which showed significant positive (+) and negative (-) associations for both males and non-pregnant females with serum uric acid (-), serum iron (-), RBC count (-), blood urea nitrogen (+), and lymphocyte count (+). Other significant associations were observed for either males or non-pregnant females. Among pregnant females, perchlorate was significantly associated with blood urea nitrogen (+) and serum iron (-). These associations may be indicators of perchlorate’s potential effect on several biological systems, which when considered in total, may implicate perturbation of iron homeostasis.