Background/Aims: Diabetic nephropathy is the leading cause of end-stage renal disease and accounts for 30∼40% of patients requiring maintenance dialysis, thereby increasing the burden on health insurance programs. Diabetic nephropathy is also the strongest predictor of cardiovascular morbidity and mortality. The aim of this study was to examine whether angiopoietin-2 (Angpt2), a modulator of endothelial function, affects the clinical outcomes of diabetic patients. Methods: This study enrolled 236 patients with diabetes mellitus with estimated glomerular filtration rate (eGFR) < 60ml/min/1.73m2 from January 2006 to December 2011, who were followed until June 2017. Clinical outcomes included renal outcomes (commencing dialysis and rapid decline in renal function (eGFR decline > 3 ml/min per 1.73 m2/year)), major adverse cardiovascular events (MACEs), and all-cause mortality. Results: Over a mean follow-up period of 3.9±2.7 years, 135 (57.2%) patients commenced dialysis, 106 (44.9%) had rapid decline in renal function, and 50 (21.2%) had MACEs or died from all-causes. Log-formed Angpt2 was significantly associated with increased risks of commencing dialysis (HR: 3.91, 95% CI: 1.56-9.76), rapid renal function decline (OR: 6.81, 95% CI: 1.06-43.88), and MACEs or all-cause mortality (HR: 6.34, 95% CI: 1.18-33.97) in the adjusted analysis. Patients in the highest quartile had hazard ratios of 2.90 and 3.11 for commencing dialysis and rapid renal function decline, respectively, compared to those in the lowest quartile after adjustments. Similar significant dose-response results were found in composite outcomes of either MACEs or all-cause mortality. Conclusion: Angpt2 is an independent predictor of adverse clinical outcomes in diabetic patients. Further studies are needed to identify the pathogenic role of Angpt2 in renal deterioration and cardiovascular complications of diabetes mellitus.