In this study, the levels of Zn2+, total protein and albumin in the serums of students with temporarily examination stress without any physical illnes were determined and the relationship between these values was evaluated. Furthermore, the change in the activity of carbonic anhydrase metaloenzyme with Zn2+ and in the rates of carbonic anhydrase I and carbonic anhydrase II were also investigated. With this aim, blood samples were taken from 100 students just before examination and from 20 control subjects. Zn2+ levels were determined enzymatically, while total protein and albumin assays were done with an autoanalyzer. Carbonic anhydrase activity was measured by Maren＇s method. The levels of Zn2+ in the serum of students experiencing examination stress were significantly lower than those of the control group, (t = 3.958, P < 0.001) whereas there was no significant difference between the levels of total protein in the two groups (t = 0.95, P > 0.05) or in the albumin amounts. In the stress group, the level of correlation between Zn2+ and total protein was significant (r = 0.720, P < 0.05). Carbonic anhydrase activity in the stress group was significantly lower than it was in the control group (t = 6.82, P < 0.001), and variation in rate of carbonic anhydrase-I and carbonic anhydrase-II was highly significant as well (t = 4.84, P < 0.001).