Summary The effect of adrenaline upon leucocyte, erythrocyte, and eosinophil count, and upon glucose, hemoglobin, and hematocrit levels in dairy calves was studied; also, the difference in response to adrenaline treatment of these blood characters between individual calves was analyzed. No significant changes were apparent from this treatment in leucocyte, hemoglobin, eosinophil, or erythrocyte values. However, certain trends were apparent. Glucose and hematocrit values were significantly increased by the treatment. Only hematocrit change following treatment with adrenaline appeared to offer promise as an indicator of individual calf response to stress.