Retinol-binding protein 4 (RBP4) is a novel adipocytokine. It was observed that retinoid intoxication was related to acute attacks of gout. Furthermore, animal study has shown that colchicine inhibits RBP secretion. The aim of this study was to explore the association between RBP4 level and metabolic parameters especially uric acid in patients with type 2 diabetes mellitus. Serum RBP4 level was measured by a commercial competitive enzyme-linked immunosorbent assay kit, and its correlation with clinical and metabolic parameters was analyzed. Data on 885 subjects were used in the analysis. Pearson correlations revealed that serum RBP4 level correlated positively with age, waist circumference, waist-to-hip ratio, systolic blood pressure, total cholesterol, triglyceride, uric acid, creatinine, and urine albumin-to-creatinine ratio. Serum RBP4 level correlated negatively with estimated glomerular filtration rate but did not correlate with body mass index, homeostasis model assessment, A(1C), or high-sensitivity C-reactive protein. Multiple linear regression analysis with serum RBP4 level as the dependent variable revealed that total cholesterol, triglyceride, uric acid, and albumin-to-creatinine ratio correlated independently and positively with serum RBP4 level and that estimated glomerular filtration rate correlated independently and negatively with serum RBP4 level. In conclusion, RBP4 level was independently associated with uric acid level.