Chronic obstructive pulmonary disease (COPD) is one of the most common chronic diseases and represents an important cause of morbidity and mortality. The main aim of this study is no know the alterations in serum vitamin C, erythrocyte glutathione activity and MDA in controls and chronic obstructive pulmonary disease patients. A retrospective study includes 120 subjects, comprising of 60 healthy controls and 60 COPD cases. Among 60 COPD cases 30 were chronic bronchitis patients and 30 were emphysema patients. Vitamin C was estimated by 2, 4 – Dinitrophenyl Hydrazine Method, Erythrocyte reduced glutathione was estimated by Ernest Beutler et al method and malondialdehyde by Kei Satoh method. The Pearson’s correlation coefficient for various antioxidants in COPD cases is evident that there is a positive correlation between vitamin C vs. erythrocyte reduced glutathione cases and is highly significant. It is also evident that there is a negative correlation between erythrocyte reduced glutathione vs. MDA and vitamin C vs. MDA cases and is highly significant. The present study revealed that there was an increased oxidative stress in patients with COPD, when compared with controls and also decreased levels of antioxidants like vitamin C and erythrocyte reduced glutathione activity in COPD patients, when compared with controls.