The objective was to investigate the effect of storage parameters on serum glucose in blood samples from four species. Blood specimens were divided into 7 no-additive tubes and serum separated from one sample after one hour (reference sample). Remaining samples were stored at 4C and 25C, then centrifuged and serum glucose measured at 2, 4, and 8 hours post-collection. Serum glucose declines for all samples stored at 4C were not significantly different, except for the 8 hour samples from sturgeon and dogs. At 25C, serum glucose was comparable to reference values at 2 hours in the horse, sturgeon, and alpaca, but significantly lower at 4 and 8 hours in those species and at all time points in dogs. Storage at 4C limits serum glucose decline for at least 4 hours in all species tested. At 25C, serum-clot contact time should not exceed 1 hour in dogs and 2 hours in horses, alpacas, and sturgeon.