Objective To describe trends in the use of percutaneous coronary intervention (PCI) following the COURAGE trial, which found that medical therapy is as effective as PCI for patients with stable angina. Data Sources We used the National Hospital Discharge Survey; inpatient and outpatient discharge data from Florida, Maryland, and New Jersey; and the English Hospital Episode Statistics database. Study Design We report trends in PCI volume by diagnosis (stable angina vs. unstable angina or AMI) before and after publication of the COURAGE trial. Principal Findings The number of PCIs in patients without a diagnosis of AMI or unstable angina in Florida, Maryland, and New Jersey declined from 48,000 in 2006 to 40,000 in 2008 (−17 percent). There was no change in the number of PCIs in patients with a diagnosis of AMI. We observed similar patterns in U.S. community hospitals. PCI volume did not decline in England. Conclusions PCI volume declined after publication of the COURAGE trial. The experience of the COURAGE trial suggests that comparative effectiveness research can lead to cost‐saving changes in medical practice patterns. However, there are many patients with stable coronary disease who continue to receive PCI post‐COURAGE.