It is of interest to evaluate the association of orthodontic tooth movement with concentration of leptin in Gingival Crevicular Fluid (GCF).Thirty orthodontic patients of both genders with equal sample size were included for the present study. Concentration of leptin was assessed at baseline (T0), 1 hr after application of force (T1), 24 hours later (T2), 7 days after application of force (T3), and 1 month after application of orthodontic force (T4). Using strips of filter paper, GCF was collected from the gingival sulcus on distal aspect of the right maxillary canine. Distalized tooth movement was evaluated by measuring the difference on dental casts, at baseline and one month after force application. One-way ANOVA with Bonferroni correction and Pearson's correlation test were used to analyze the data. Average concentration of leptin in GCF raises from baseline (T0) to 1 hours after application of force (T1), then increased to peak after 24 hours (T2), and declined to a minimum value after 7 days (T3) and again raises after 1 month (T4), closer to the base line value (T0), and this was statistically significant (P < 0.05). There was significant association of the overall average concentration of leptin to degree of tooth movement (correlation coefficient = 0.625). There was a biphasic change in GCF leptin concentration during one cycle of orthodontic force application, thus, a significant association between rates of tooth movement with GCF leptin concentration is noted.