To assess the gingival cervicular fluid (GCF) myeloperoxidase (MPO) levels in smoker patients with chronic Periodontitis before and after treatment. Materials and methods: A total of 30 patients were selected aging from 25-45 years. They were divided into two equal groups, 15 Non smoker patients acting as a positive control group and another 15 smoker patients acting as test group. The levels of GCF MPO were analyzed for all patients before treatment and following non-surgical periodontal treatment. Results: MPO was significantly higher among smokers and nonsmokers with chronic periodontitis before treatment than following nonsurgical therapy. However, the results were still higher among smoker patients than nonsmokers. The reduction in the level of MPO after treatment was statistically significant in nonsmokers as compared to smokers. Conclusion: Nonsurgical periodontal therapy is associated with reduction in MPO levels in GCF of both smokers and nonsmokers with Periodontitis where the level of MPO in GCF is higher in smokers than nonsmokers with Periodontitis