The Tasmanian devil (Sarcophilus harrisii) is the largest extant carnivorous marsupial. The Tasmanian devil is currently listed as endangered and is under threat from a contagious cancer. The aims of the study were to determine hematology and blood chemistry reference intervals for captive Tasmanian devils and determine the influence of three biological factors on blood variables. Hematology and blood chemistry data were analyzed retrospectively from medical reports obtained from Taronga Zoo. Samples were analyzed using current technology at the time of collection. Thirty seven variables were analyzed for 104 blood samples from 1992 until 2015. Data were statistically analyzed for differences between age, gender and season. Generally Tasmanian devils have higher serum concentrations of albumin (ALB) and creatinine and lower alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and amylase (AMY) compared with other dasyurids. Younger animals tended to have significantly higher serum concentrations of ALP, AST and phosphorus, while total protein and globulin activity in younger animals was less than in older animals. Hemoglobin, total protein and AST concentrations were influenced by season, with higher concentrations observed in either spring or summer. Lymphocyte, and erythrocyte counts, and serum concentrations of lipase and AMY were significantly higher in females compared with males. The reference ranges determined here can be used in the health assessment of captive Tasmanian devils and for those used in translocation programs in the future.