Background: Cardiac Allograft Vasculopathy (CAV) is characterized by vascular inflammation and intimal proliferation which results in luminal stenosis and myocardial infarction. During vascular inflammation elaboration of several cytokines and differential expression of growth factors have been noted. CAV remains the major threat to long-term graft survival. CD4 and CD8 T-cell subsets play a significant role in the development of transplant rejection. Chronic transplant rejection often leads to development of CAV. A new CD4 effector cell subset that produces IL-17 (Th17) has been shown to be up-regulated in the murine system in the setting of CAV. This study assesses the level of IL-17 in cardiac transplant patients with and without CAV as compared to nontransplanted controls. Methods: Levels of IL-17, IL-6, MCP-1 were measured by ELISA in plasma of four nontransplanted controls, nine cardiac allograft recipients with CAV (HT-GVD) and eight post transplant subjects without a diagnosis of CAV (HT-No GVD). All post transplant patients were immune suppressed with cyclosporine. HT-GVD patients were 1-15 years post transplant while HT-No GVD subjects were 1 – 10 years post transplant. Results: IL-17, MCP-1 and IL-6 were significantly down regulated in HT-GVD subjects compared to the HT-No GVD subjects (p <0.001) but not significant between controls and HT-No GVD (p = ns). Conclusions: A decrease in IL-17 in HT-GVD subjects as compared to HT-No GVD in the presence of cyclosporine treatment could be a consequence of down regulation of IL-6. It is likely that cyclosporine differentially regulates pro inflammatory molecules in the setting of graft vascular disease.