1. The prairie dog has been used extensively for the study of gallstone genesis and gallstone dissolution therapies, and has recently been implicated in an effort to prevent total parenteral nutrition-associated cholelithiasis with intravenous chenodeoxycholate. 2. Towards this effort, it is important that a range of normal blood chemistry values be reported for the prairie dog. This paper reports the mean values for a complete blood cell count, electrolytes, blood urea nitrogen, creatinine, calcium, phosphorus, liver enzymes, total bilirubin, protein, albumin, cholesterol, triglycerides and lipids for 45 adult prairie dogs. 3. The prairie dog has normochromic, microcytic blood with an increased number of red blood cells. The prairie dog also has a high concentration of small platelets. 4. The prairie dog has a higher CO2 concentration with a slightly increased potassium concentration than is found in man. The anion gap is 12 with a calculated serum osmolality of 316. The BUN concentration is elevated with a 3-fold increase in the AST concentration. 5. The prairie dog has lower serum values for cholesterol, VLDL and LDL cholesterol than man. In the prairie dog, HDL cholesterol consists of 67% of the total cholesterol concentration and the LDL and HDL ratio is 0.3.