Background: Periodontitis is result of cumulative exposure of dental plaque, thus the main aim of periodontal therapy is the prevention of plaque accumulation and maintain periodontal health. The clinical effect of scaling and root-planning (SRP) are well documented .Antimicrobial agents act as an adjunct to periodontal therapy. One of the most frequently used antimicrobial agents is chlorhexidine gluconate (CHX), it is a broad spectrum antiseptic with a pronounced antimicrobial effect Clinical improvements after SRP are associated with microbiological changes that include a decrease in microbial load and a mean percentage change of certain periodontal pathogens , such as Treponema denticola, Porphyromonas gingivalis and Tarnella forsythus. These species are gram negative anaerobes which possess, an enzyme capable of hydrolyzing synthetic trypsin substrate, BANA. Methods: This study included 30 individuals who were randomly distributed in two groups test (SRP + CHX) and control (SRP) Results: The results of the study stated that the treatment with SRP and CHX improved clinical and microbiological parameters compared to the SRP alone as a monotherapy. Conclusion: CHX rinsing and repeated professional plaque removal could have equivalent therapeutic benefits, the use of CHX offers the great advantage of not requiring the patient's presence in the dental office.