Blood glucose level of Thai elephant (Elephas maximus indicus), a subspecies of the Asian elephant has not been reported. The aim of this study was to find (or determine) relationship between blood glucose level and other factors of captive Thai elephants such as age, sex, body condition score and body weight. The blood was collected from 52 individuals and blood glucose levels were determined using a blood glucose meter (Acuu-chek®). The results show that the mean blood glucose level of the elephant was (mean±SEM) 111.79±4.38mg/dL (range: 72.5-220.5 mg/dL). The mean blood glucose level of the males (108.01±6.97 mg/dL, range 72.5-194.0 mg/dL) and the females (115.02±5.57 mg/dL, range: 78.0-220.5 mg/dL). Comparison of serum glucose levels and other factors, found blood glucose levels correlated with body weight significantly (P < 0.05).