Background: An alternative approach to conventional antimicrobial or antiseptic agents in the suppression of subgingival bacteria is to inhibit the growth by changing the subgingival ecology. The subgingival environment has been demonstrated to have a low redox potential which supports the growth and survival of subgingival anaerobic bacteria. Redox agents, such as methylene blue raise the redox potential of an ecosystem. Aim: To study the effects of methylene blue incorporated into chitosan strips on clinical parameters and on Porphyromonas. gingivalis, Prevotella. intermedia, Fusobacterium. nucleatum and Capnocytophaga. Materials & Methods: A total of 40 sites from 20 patients. were included in a split-mouth design. 40 sites were divided into Group A (experimental) and Group B (control). Clinical parameters - plaque index, gingival index, probing pocket depth were recorded. Microbiological evaluation was done by Gram’s stain and culture. The clinical and microbiological parameters were recorded on days 0, 7, 15 and 30. Results: The Groups A and B showed a reduction in clinical parameters plaque index, gingival index and probing pocket depth. Gram’s stain revealed that there was a significant increase in gram positive and negative cocci and decrease in gram negative bacilli in both the groups. Group A showed highly significant changes towards the healthy flora. Culture analysis showed that all the three organisms were predominant except Porphyromonas. gingivalis in both the groups. At the end of the study, there was a decrease in F. nucleatum, Capnocytophaga and P. intermedia and absence of P. gingivalis in both the groups. But experimental sites showed highly significant reduction compared to control sites. Conclusion: Methylene blue incorporated in chitosan stips can be used as an adjunctive treatment in adult periodontitis. Further long term studies are recommended to evaluate the known sustained effect of the redox agent.