BACKGROUND: Percutaneous coronary intervention (PCI) is frequently performed in elderly patients, but little is known about its impact on overall health and quality of life. OBJECTIVE: To examine changes in health-related quality of life among elderly patients after PCI. Design: Observational study. SETTING: 75 U.S. hospitals. PATIENTS: Participants in two clinical trials of PCI. MEASUREMENTS: Health-related quality of life was assessed by using the Medical Outcomes Study Short Form (SF-36) survey and the Seattle Angina Questionnaire at baseline, 6 months, and 1 year. RESULTS: Serial data on health-related quality of life were available for 295 elderly (> or =70 years) and 1150 nonelderly (<70 years) patients. At 6 months, physical health had improved in 51% of elderly patients and mental health had improved in 29%. Cardiovascular-specific health status had improved in 58% to 75% of elderly patients. Improvement did not significantly differ between elderly and non-elderly patients at 6 months or 1 year. CONCLUSIONS: Elderly patients selected for participation in a trial of PCI had substantial improvements in health-related quality of life after PCI that were similar to those in younger patients.