During scuba diving, difficult physical activity, oxidative stress caused by hyperoxia and cold exposure affects the health status of divers. Dynamic thiol-disulphide homoeostasis has never been investigated before on compressed air diving in a hyperbaric chamber. We aimed to evaluate acute effect of diving on thiol/disulphide homeostasis in divers and compare the chronic effects of dives with healthy individuals. Seventeen of the underwater technology students were admitted to the dive pressure chamber for a 5-minute deep-air dive at 40 meters. Pre-post diving samples were taken to investigate the acute stress of diving. In order to investigate chronic stress, we compared the results of 17 medical school students. Demographic data of the students of both universities were similar. Increase in Dynamic ThiolDisulphide Homoeostasis for acute effect were statistically significant ((403.5 +/- 5.4vs.420.2 +/- 2.5, p=0.012; 18.6 +/- 2.7vs.25 +/- 1, p=0.040; 5.1 +/- 0.7vs.6.8 +/- 0.3, p=0.042; 4.5 +/- 0.6vs.5.9 +/- 0.2, p=0.051; 91.1 +/- 1.2vs.88.1 +/- 0.4, p=0.042). Increase in native thiol values between serum before and after diving are not statistically significant (366.4 +/- 1.5 vs.370.2 +/- 2.1 p=0.14). Difference in Dynamic Thiol-Disulphide Homoeostasis for chronic effect were not statistically significant (403.5 +/- 5.4vs.408.5 +/- 4.8, p=0.491; 18,6 +/- 2.7vs.17.2 +/- 2.2, p=0.685; 5.1 +/- 0.7vs4.6 +/- 0.6, p=0.663; 4.5 +/- 0.6vs.4.13 +/- 0.5, p=0.626; 91,1 +/- 1.2vs.91.7 +/- 1, p=0.663). Difference in native thiol values between serum study and control groups were statistically significant (366.4 +/- 1.5vs.374.2 +/- 3.3; p=0.045). The stress during the air dives creates acute oxidative stress to the diver and disrupts the dynamic thiol/disulphide balance, but there were no changes observed to disrupt the homeostasis of thiol/disulphide chronically.