Hematocrit values for K3EDTA-preserved whole blood from black bears (Ursus americanus) were found to increase during refrigerated storage causing error in delayed laboratory analysis. This error was quantified using a regression type model based on repeated hematocrit testing of 66 blood samples over time. The model proved to fit quite well and provided corrected-to-day-zero hematocrit values for 42 samples from which day-zero values were not available.