Photodynamic therapy (PDT) is a new, non-invasive therapeutic procedure that employs photosensitizers, light of precise wavelength, and which leads to production of singlet oxygen to eradicate pathogenic microbes. The present study is a randomized split mouth prospective double blinded 6 month followup trial evaluating the efficacy of single application of PDT, Diode laser as an adjunct to conventional SRP in the treatment of chronic periodontitis patients receiving initial periodontal therapy. Methods: This study was a single center