Background: Smoking, which is an important risk factor for periodontitis, induces oxidative stress in the body and causes an imbalance between reactive oxygen species (ROS) and antioxidants, such as superoxide dismutase (SOD). In the present study, we set out to assess periodontal disease in smoking and non-smoking subjects evaluated by estimating the level of SOD enzyme. Methods: Fifty patients in the age range of 30 to 50 years were selected Clinical parameters recorded were plaque index (PI), papillary bleeding index (PBI), probing pocket depth (PPD), and clinical attachment loss (CA L).The patients were classified into five groups each group included 10 patient, based on smoking status (non-smokers healthy patients, light smokerswith chronic gingivitis, heavy smokers with chromc gingivitis, light smokers withchronic periodontitis,heavy smokers with chronic periodontitis). Gingival crevicular fluid (GCF) samples were collected to analyze the level of SOD levels. Results: The mean levels of SOD in the GCF of smokers were decreased compared to controls. Intra- and intergroup analyses showed a significant reduction in the levels of SOD in the GCF of heavy smokers compared to light smokers and the control group. There was a correlation between SOD and PPD and CAL in smokers with periodontitis. Conclusions: SOD levels in GCF are reduced in smokers in particular heavy smokers. The benefits of reduced smoking and improved antioxidant levels may motivate smoking cessation