Background: Chronic periodontitis (CP) is an infectious disease resulting in inflammation within the supporting structures of teeth, loss of attachment and bone resorption. Lycopene is a free radical scavenger and has antioxidant and anti-inflammatory properties. In periodontitis, isoprostane has been suggested to be a marker of inflammation And GCF 8-isoprostane levels are more revealing than serum or saliva levels Aim: The aim of this study was to determine the effectiveness of local lycopene as an adjunct to scaling and root planning in the treatment of chronic periodontitis. Subjects and methods : Forty chronic periodontits patients were involved in this study. Clinical parameters (Gingival Index, Plaque Index, Clinical Attachment Loss, and Probing Pocket Depth) were recorded at baseline and six weeks after treatment. Gingival crevicular fluid samples were collected at baseline and six weeks after treatment and 8-isoprostane level was assessed. All patients received scaling and root planning. Results: at baseline, there were no significant difference regarding clinical parameters (gingival index, plaque index, clinical attachment loss, probing pocket depth), and 8-isoprostane level in gingival crevicular fluid among studied periodontitis groups. Six weeks after treatment, clinical parameters showed significant reduction in group 1, 2, 3 in clinical parameters and GCF 8-isoprostane level..  Conclusion: Locally application of lycopene as adjunctive therapy to scaling and root planning could be an effective treatment of chronic periodontitis. Key words: Chronic periodontitis,lycopene , local drug delivery, 8-isoprostane, gingival crevicular fluid.