We compared serum glucose concentration and percent glycosylated hemoglobin (GH) in captive and wild white-tailed deer (Odocoileus virginianus) to determine stability of glucose relative to GH. Temporal changes in levels of serum glucose and GH were ascertained from serial blood samples collected from three captive deer over a 2-week period. State of glycemia also was determined for 17 wild deer that were collected from three populations in southeastern Oklahoma and southwestern Arkansas (USA). Concentration of serum glucose of captive deer decreased (P = 0.04) from 190.4 to 155.8 mg/dl over the 2 weeks; percent GH did not differ temporally (P = 0.30). Percent GH of wild deer did not differ (P = 0.23) when deer were separated into 2 groups (high and low state of glycemia) based on the median serum glucose concentration. We found a significant difference (P = 0.04) in percent GH among wild deer populations; serum glucose concentration did not differ (P = 0.72) among populations. Our results indicate that percent GH is more stable than serum glucose concentration and may be useful in population comparisons of nutritional condition.