Chronic kidney disease (CKD) is associated with increased risk of cardiovascular disease and death. We evaluated the association between CKD and severity of coronary artery stenosis by calculating SYNTAX Score in patients with left main coronary artery and/or 3-vessel coronary artery disease. Coronary angiograms of 217 patients were assessed. Chronic kidney disease was staged using the estimated glomerular filtration rate (eGFR, mL/min per 1.73 m(2)) prior to coronary angiography. Patients were divided into 5 groups according to the National Kidney Foundation Kidney Disease Outcome Quality Initiative (NKF KDOQI) Clinical Practice Guidelines (14). Patients with eGFR >90 mL/min per 1.73 m(2) (group 1), patients with eGFR 60 to 89 mL/min per 1.73 m(2) (group 2), patients with eGFR 30 to 59 mL/min per 1.73 m(2) (group 3), patients with eGFR >15 to < 30 per 1.73 m(2) and dialysis patients with eGFR < 15 per 1.73 m(2) were combined as group 4. The risk of significant lesion complexity increased progressively with decreasing kidney function (P = .001). Estimated glomerular filtration rate was a strong predictor of higher SYNTAX Score.