Background and objectives: Periodontal disease is the most common disease associated with microbial infection with the destruction of supporting structures. This study was carried out to evaluate the effectiveness of green tea as a mouthwash in the management of chronic periodontitis in comparison to chlorhexidine mouthwash. Patients and methods: A randomized controlled trial on 45 healthy humans with mild to moderate localized chronic periodontitis. They were randomly assigned into 3 equal groups (15 patients each), and they all received scaling and root surface debridement treatments. Group A used prepared green tea 5% as mouth wash for 2 weeks, group B used chlorhexidine mouthwash 0.12% for 2 weeks and group C did not use any mouth wash. Intra-oral clinical examination and blood samples collection were done for all patients for estimating the biochemical parameters C-reactive protein, alkaline phosphatase, Malondialdehyde at baseline and 30 days after periodontal therapy. For statistical analysis, SPSS program was used. Results: The study groups showed significant reduction in clinical periodontal parameters and inflammatory markers after 30 days of periodontal therapy (P<0.001). A significant difference was seen between group A and group B in relation to clinical periodontal parameters and inflammatory markers after periodontal therapy P<0.05, while the difference between group B and group C was non-significant in relation to gingival index, clinical attachment level, C-reactive protein, alkaline phosphatase, and Malondialdehyde. Conclusion: Green tea as a mouthwash could be an appropriate and effective choice as an adjunctive measure in the treatment of chronic periodontitis.