Background: Antioxidant system enzyme activity and polymorphism were investigated in Chronic Obstructive Pulmonary Disease (COPD), which is increasingly prevalent both in the world and our country. Methods: Malondialdehyde (MDA) was measured to determine lipid peroxidation, while Catalase (CAT), Paraoxonase (PON) and Superoxide Dismutase (SOD) enzyme activities were measured to determine antioxidant activity. For molecular analysis, leukocytes were separated and DNA was isolated from cell nuclei and the targeted genes were amplified by using PCR. Targeted There was no significant difference in genotype distribution for CAT, SOD, PON55 and PON192 polymorphisms between groups. Conclusion: In conclusion, COPD patients were found to have a deficiency in the antioxidant defense system. This will lead to the development of oxidative stress in patients and the complications of COPD. There was no polymorphic difference between the control group and South African patients living in Adiyaman in COPD whose genetic characteristics were not fully explained.