Background. Long-termconsequences of kidney donation are not well known. Most of the studies published were focused on renal risk. In this prospective study, we investigated the changes in cardiovascular function after kidney donation. Methods. Thirty-eight living kidney donors were included. In addition to 24-hr ambulatory blood pressure monitoring, serum interleukin-6, vascular cell adhesion molecule (VCAM), and asymmetric dimethylarginine levels were measured. Endothelial function was examined bymeasuring ischemia-induced flow-mediated dilation (FMD) of the brachial artery. All studieswere repeated at 3 months and 12 months after kidney donation. Results. The mean serum interleukin-6 levels, both at 3 months and 12 months, were significantly increased as compared to the baseline (P = 0.007 and P < 0.001, respectively). The mean serum asymmetric dimethylarginine (P < 0.001) and VCAM levels (P < 0.001) at 12 months were significantly increased as compared to baseline. FMD values at 1 year (9.3% +/- 7.1%) were significantly decreased as compared to 3 months (13.0% +/- 6.0%, P = 0.001) and baseline (13.9% +/- 6.3%, P = 0.002). In multivariate analysis, serum uric acid (P = 0.001), estimated glomerular filtration rate (P = 0.027), and VCAM (P = 0.014) levels were the independent predictors of FMD 12 months after kidney donation. Conclusion. Our findings suggest that kidney donation might increase the cardiovascular risk in kidney donors.