Abstract: The oxidative stress caused by free radicals and reactive oxygen species released during smoking can play a significant role in pathogenesis and development of Chronic Bronchitis. This study is conducted to evaluate serum levels of Malondialdehyde (MDA) a lipid peroxidation product as a marker of oxidative stress and vitamin C major antioxidant in body in chronic bronchitis patients and healthy controls. Comprised of 80 subjects, 40 healthy controls and 40 chronic bronchitis cases were included. Kei Satoh method used for measuring MDA and Serum vitamin C was estimated by method 2,4-Dintrophenyl hydrazine method Serum MDA a lipid peroxidation product from cell membrane considered as marker of oxidative stress was elevated in chronic bronchitis patients when compared to healthy controls where as serum level of vitamin C major antioxidant significantly decreased in chronic bronchitis patients when compared to controls.. MDA maker is of oxidative injury significantly increased in chronic bronchitis cases which is likely associated with active smoking habit and also be due to systemic inflammation. The decrease in level of antioxidant capacity in chronic bronchitis patients appears likely consequence of higher oxidative stress and increased consumption of antioxidants. By stopping smoking and advising antioxidant rich food may halt the further progression of chronic bronchitis disease.