There are limited data on the validity of the Thrombolysis In Myocardial Infarction (TIMI) risk score for unstable angina pectoris (UAP)/non-ST-elevation myocardial infarction in patients with moderate to advanced chronic kidney disease (CKD), including patients using dialysis. Accordingly, we evaluated the prognostic ability of the TIMI risk score in consecutive patients across the entire spectrum of CKD who presented with UAP or non-ST elevation myocardial infarction and underwent percutaneous coronary intervention from July 1, 1999, to June 30, 2007. Patients were categorized by estimated glomerular filtration rate (eGFR) > or = 60 (n = 4,938), 30 to 59 (n = 1,592), and <30 ml/min/1.73 m2 (n = 202) and use of dialysis (n = 208). Hazard ratios of all-cause mortality associated with TIMI risk score levels (0 to 2, 3 to 4, > or = 5) were calculated within each eGFR category. Over a median follow-up of 3.2 years, 813 deaths occurred. For patients with an eGFR > or = 60 ml/min/1.73 m2, race- and gender-adjusted hazard ratios of mortality associated with TIMI risk scores of 3 to 4 and > or = 5 compared with 0 to 2 were 2.92 (95% confidence interval [CI] 1.93 to 4.40) and 4.26 (95% CI 2.82 to 6.43), respectively. Analogous hazard ratios were 1.26 (95% CI 0.80 to 1.98) and 1.77 (95% CI 1.13 to 2.78) for patients with an eGFR of 30 to 59 ml/min/1.73 m2, 2.23 (95% CI 0.71 to 6.94) and 2.83 (95% CI 0.89 to 8.99) for patients with an eGFR <30 ml/min/1.73 m2, and 3.16 (1.33 to 7.48) and 3.67 (95% CI 1.52 to 8.86), respectively, for patients on dialysis. In conclusion, the TIMI risk score for UAP/non-ST elevation myocardial infarction discriminates mortality risk across the full range of CKD, including patients on dialysis.