To assess the association and prognostic value of adipokines (adipocyte-secreted peptide hormones) in renal cell carcinoma (RCC).Plasma samples from 54 RCC patients and 25 age-matched healthy controls were analyzed for levels of adipokines (adiponectin, leptin, retinol-binding protein 4 [RBP4], and nicotinamide phosphoribosyltransferase [NAMPT]). Baseline characteristics and adipokine levels were compared between patients and controls. The effect of adipokine levels on RCC severity was also investigated.Medians (patients/controls) were body mass index: 24.6/23.5kg/m2, serum glucose: 111/93mg/dl, and high-density lipoprotein: 43/53mg/dl, and significantly differed between the 2 groups. Median levels (patients/controls) of adipokines were adiponectin: 4.36/8.84ug/ml, leptin: 2.91/2.92ng/ml, RBP4: 30.27/16.17ug/ml and NAMPT: 2.26/2.06ng/ml; adiponectin, RBP4 and NAMPT (but not leptin) were independently associated with RCC in logistic regression models, and only serum NAMPT was significantly associated with RCC severity (T stage).Lower plasma levels of adiponectin, and higher levels of RBP4 and NAMPT, are strongly correlated with RCC, indicating that these adipokines could be used as biomarkers for RCC.