The aim of the present study was to assess GCF leptin concentrations in healthy, chronic and aggressive periodontitis and to explore leptin levels in both healthy and diseased sites in aggressive periodontitis. Subjects and Methods: A total of thirty subjects were selected based on their body mass index for the study. The subjects were divided into three groups of 10 patients each: Group I: Healthy periodontium, Group II: Chronic periodontitis and Group III: Aggressive periodontitis. GCF samples were collected to estimate leptin levels using enzyme-linked immunosorbent assay kit. Results: Control group showed the statistically significant highest mean leptin level. This was followed by the chronic periodontitis group. Aggressive periodontitis group showed the statistically significant lowest mean leptin level. Conclusion: Leptin levels in GCF decreases as periodontal tissue destruction increases. Leptin is site specific in aggressive periodontitis. All these findings confirm the possible protective role of leptin in periodontal health.