Background: Kawasaki disease is an acute febrile illness with systemic vasculitis which primarily affects children, We examined the production of leptin in plasma and gene expressions of CXC chemokines in peripheral blood mononuclear cells from patients with Kawasaki disease. Methods: Consecutive 39 samples from 13 patients according to the different clinical stages (acute, subacute, convalescent) of Kawasaki disease were collected. The plasma leptin levels according to clinical stages of Kawasaki disease were examined by ELISA and the expression of IP-10, Mig and IL-8 mRNAs in 39 samples (13 samples of each stage) from 13 cases were examined by RT-PCR. Results: There were not significant changes of plasma leptin levels according to the clinical stages of Kawasaki disease. The mean values of plasma leptin concentrations during each of the stages (n=13, p>0.05, pg/ml) were 335.8±549.0 in acute, 358±347.6 in subacute, and 443.6±645.9 in convalescent stage. The mRNAs of IP-10, Mig, and IL-8 were expressed in 13/13 (100%), 2/13 (15%), 9/13 (69%) during acute stage, 13/13 (100%), 6/13 (46%), 13/13 (100%) during subacute stage, and 13/13 (100%), 4/13 (31%), 10/13 (77%) during the convalescent stage, respectively. In three patients, the production of leptin and expression of IP-10 mRNA were dramatically decreased according to the process of the clinical stages. In five patients with prominent cervical lymphadenopathy, the expression of IL-8 mRNA during the subacute stage was more elevated than the acute and convalescent stages. Conclusion: This data suggests that the production of leptin and the gene expressions of IP-10, Mig and IL-8 seem to have no significant correlation to the clinical stages of Kawasaki disease. However, expression patterns of IP-10, Mig and IL-8 mRNA may be related to the specific clinical manifestations, and the expression of IP-10 may also be correlated to leptin levels with pericardial involvement.