Coronary artery disease is the main cause of death in patients with chronic kidney disease (CKD). The poor prognosis associated with acute coronary syndrome (ACS) in these patients has been related to therapeutic nihilism. This study included 2,357 patients with ACS who had percutaneous coronary intervention. According to their creatinine clearance and medical history, they were divided into 3 groups: dialysis (n = 73); CKD (n= 293); and control (n= 1,991). Rates of cardiovascular events were recorded during a 1-year follow-up period. Patients in all groups received similar contemporary therapy for ACS, including percutaneous coronary intervention and optimal medial therapy. On admission, patients with CKD and patients on dialysis more often presented with cardiogenic shock (p = 0.05 and 0.02, respectively). A graded increase in the rate of major adverse cardiovascular events at 1 year was observed with decreasing renal function (control 13%, CKD 22.9%, dialysis 45.2%, p <0.001 for all comparisons). In multivariate analysis, patients with CKD and on dialysis were significantly associated with 1-year major adverse cardiac events with adjusted hazard ratios of, respectively, 1.5 (95% confidence interval 1.1 to 2.1; p = 0.009) and 2.7 (95% confidence interval 1.7 to 4.1; p <0.001). In conclusion, despite optimal contemporary medical therapy and revascularization, the prognosis of patients with CKD and, in particular, of patients undergoing dialysis, remains poor.