Health data for free-living eastern box turtles (Terrapene carolina carolina) at the Maryland Zoo in Baltimore were analyzed. One hundred and eighteen turtles were captured on or near zoo grounds over the course of 15 yr (1996–2011), with recapture of many individuals leading to 208 total evaluations. Of the 118 individuals, 61 were male, 50 were female, and 7 were of undetermined sex. Of the 208 captures, 188 were healthy, and 20 were sick or injured. Complete health evaluations were performed on 30 turtles with physical examination records, complete blood counts (CBCs), and plasma biochemistry profiles. Eight animals were sampled more than once, yielding 40 total samples for complete health evaluations of these 30 individuals. The 40 samples were divided into healthy (N = 29) and sick (N = 11) groups based on clinical findings on physical examination. Samples from healthy animals were further divided into male (N = 17) and female (N = 12) groups. CBC and biochemistry profile parameters were compared between sick and healthy groups and between healthy males and females. Sick turtles had lower albumin, globulin, total protein (TP), calcium, phosphorous, sodium, and potassium than healthy animals. Sick turtles also had higher heterophil to lymphocyte ratios. Healthy female turtles had higher leukocyte count, eosinophil count, total solids, TP, globulin, cholesterol, calcium, and phosphorous than healthy males. Banked plasma from all 40 samples was tested for antibodies to Mycoplasma agassizii and Mycoplasma testudineum via enzyme-linked immunosorbent assay. One sample from a clinically healthy female was antibody positive for M. agassizii; none were positive for M. testudineum. This study provides descriptive health data for eastern box turtles and CBC and biochemistry profile information for T. carolina carolina at and near the Maryland Zoo in Baltimore. It also reports low serologic evidence of exposure to mycoplasmosis.