This study evaluated the impact of age on care and outcomes for non-ST-segment elevation acute coronary syndromes (NSTE ACS). Recent clinical trials have expanded treatment options for NSTE ACS, now reflected in guidelines. Elderly patients are at highest risk, yet have previously been shown to receive less care than younger patients. In 56,963 patients with NSTE ACS at 443 U.S. hospitals participating in the Can Rapid Risk Stratification of Unstable Angina Patients Suppress Adverse Outcomes With Early Implementation of the American College of Cardiology/American Heart Association Guidelines (CRUSADE) National Quality Improvement Initiative from January 2001 to June 2003, we compared use of guidelines-recommended care across four age groups: <65, 65 to 74, 75 to 84, and > or =85 years. A multivariate model tested for age-related differences in treatments and outcomes after adjusting for patient, provider, and hospital factors. Of the study population, 35% were > or =75 years old, and 11% were > or =85 years old. Use of acute anti-platelet and anti-thrombin therapy within the first 24 h decreased with age. Elderly patients were also less likely to undergo early catheterization or revascularization. Whereas use of many discharge medications was similar in young and old patients, clopidogrel and lipid-lowering therapy remained less commonly prescribed in elderly patients. In-hospital mortality and complication rates increased with advancing age, but those receiving more recommended therapies had lower mortality even after adjustment than those who did not. Age impacts use of guidelines-recommended care for newer agents and early in-hospital care. Further improvements in outcomes for elderly patients by optimizing the safe and early use of therapies are likely.