Chronic renal failure is an important risk factor in acute coronary syndromes. Patients with chronic renal failure have a worse in-hospital and long-term outcome than patients with normal renal function. Although chronic renal failure is associated with other risk factors (diabetes, hypertension, high Killip class, peripheral vascular disease), multivariate analysis of several studies has consistently shown that chronic renal failure significantly and independently affects outcome in patients with acute coronary syndrome. Such patients are treated less aggressively than patients with normal renal function: beta-blockers, aspirin and statins are less frequently used in the intensive care unit. Few data are available on the immediate and long-term effects of an aggressive strategy based on early coronary angiography and subsequent revascularization in such patients. Moreover, only few patients with advanced renal disease have been enrolled in trials comparing treatment modalities in acute coronary syndrome. However, when great care is taken to avoid high contrast medium load, blood loss and periprocedural hypotension, which may result in deterioration of renal function, interventional techniques may prove to be successful in improving outcome.