The concentration of glycated hemoglobin (HbA1c) is an integrated expression of the blood glucose concentration level in the previous weeks. The levels of HbA1c were measured in 23 medical students who had to pass an examination within a few weeks. Twelve other students served as a control group. Four months later, the blood tests were repeated. In addition, serum cholesterol was measured. HbA1c levels were significantly higher in the exam group compared with the control group. The second test revealed a significant decrease in HbA1c in the exam group, while the values in the control group were stable. No differences in serum cholesterol were detected. It is concluded that HbA1c might be of value as a measure of physiological stress.