Though one of the most widely kept elasmobranchs in human care, the cownose ray (CNR; Rhinoptera bonasus), remains a species with minimal published information on hematologic reference intervals. As part of a larger study investigating the health and nutrition of the CNR, this study established a preliminary data set of plasma chemistry and hematology values specific to animals recently caught from the wild and compared this data set (intake sample) to values obtained following a period of quarantine (27–40 days) in an aquarium (exit sample). Blood samples were collected from 47 wild female (n = 46) and male (n = 1) CNR caught in pound nets off the coast of North Carolina and South Carolina. Differences between intake and exit values were analyzed. Due to the preponderance of female animals, data were not analyzed for sex differences. Plasma biochemical profiles were performed and analyzed. A select number of complete blood cell counts were performed (n = 24 from 12 animals). Statistically significant differences (P < 0.05) specific to time of sampling were determined for packed cell volume, total solids, blood urea nitrogen, sodium, chloride, potassium, phosphorus, cholesterol, glucose, and aspartate aminotransferase. Values reported are a significant expansion on the existing limited data for CNRs and will serve as a reference for health assessment of individuals both in the wild and in exhibit populations.