The aim of the study was to assess gingival crevicular fluid (GCF) leptin level in patients with chronic periodontitis versus periodontally healthy controls. The effect of non-surgical periodontal therapy on GCF leptin level in chronic periodontitis patients was evaluated. Patients and Methods: Twenty patients with chronic periodontitis (15 males and 5 females) with mean age 42.4 years (SD ±10.15) and ten periodontally healthy subjects (7 males and 3 females) with mean age 28.6 years (SD ±3.13) participated in the study. Gingival Crevicular Fluid (GCF) Samples were collected for assessment of Leptin levels at baseline before initial periodontal therapy and six weeks after the completion of therapy from the selected sites presenting CAL of 5mm or more and evidence of alveolar bone resorption in chronic periodontitis patients. Result: the GCF levels of leptin were significantly higher in healthy subjects compared to chronic periodontitis patients. No significant difference in GCF leptin levels six weeks after non-surgical periodontal treatment when compared to baseline levels. Conclusions: The GCF leptin concentration was significantly lower in disease sites in chronic periodontitis patients versus periodontally healthy controls. There was a negative correlation between GCF leptin level and gingival inflammation in chronic periodontitis patients before treatment. Non- surgical periodontal treatment induced non-statistically significant increase in GCF leptin level six weeks after treatment. Aim of the study: The aim of the study was to assess gingival crevicular fluid (GCF) leptin level in patients with chronic periodontitis versus periodontally healthy controls. The effect of non-surgical periodontal therapy on GCF leptin level in chronic periodontitis patients was evaluated. In addition possible correlation between GCF leptin level and clinical parameters of disease was analyzed.