Background and objective: Periodontal disease is caused by periodontal pathogens that colonize the dental plaque and the subsequent host-microbial interactions. The recent years have witnessed a rapid increase in the usage of Light Amplification by Stimulated Emission of Radiation (Laser) in dentistry for the treatment of periodontal diseases. The additive therapeutic effects when a photoactivated dye such as methylene blue is used in conjunction with Laser is well documented. Indocyanine green (ICG), a tri-carbocyanine that belongs to family of cyanine dyes is widely used in the fields of Ophthalmology and Cardiac imaging. Recent in vitro studies have reported its efficacy in killing potent periodontal pathogens like A. actinomycetemcomitans and P. gingivalis when combined with 810 nm diode laser. The present study aims at evaluating the effects of ICG as an adjunct to non-surgical treatment of chronic periodontitis in biofilm environment of human periodontal pockets in terms of immediate reduction in percentage of viable bacteria and at the same to quantitatively assess host tissue injury. Methods: The study included 30 patients diagnosed with chronic periodontitis. Three sites from three different quadrants were selected and assigned to three groups namely, SRP group - scaling and root planing, LASER group - scaling and root planing with application of 810 nm diode laser and ICG group - scaling and root planing with application of 810 nm diode laser and ICG at a concentration of 5 mg/mL. Primary parameters included estimation of decrease in percentage of viable bacteria at baseline, immediate post treatment and end of 1 week and Lactate dehydrogenase (LDH) levels at baseline and end of 1 week. Secondary parameters included site-specific measures of plaque, gingivitis, pocket depth (PD) and clinical attachment loss (CAL) at specific time intervals.