Coronary angioplasty is performed > 1,000 times daily in a variety of health care settings in the public and private sectors in the USA. How outcomes for this procedure differ in the Department of Veterans Affairs and the private sector is unknown. The purpose of this study was to compare outcomes of coronary angioplasty performed in hospitals in the Department of Veterans Affairs and the State of Washington. This study used administrative data from the Department of Veterans Affairs patient treatment file (n = 8,326) and the State of Washington episode of illness file (n = 6,666) and included men who underwent coronary angioplasty in 1993 and 1994. Outcomes included (1) in-hospital mortality and mortality at 10 and 30 days after hospital admission, and (2) the use of coronary artery bypass surgery at similar intervals. Patients with a principal diagnosis of acute myocardial infarction were analyzed separately. Men in the Department of Veterans Affairs had more comorbid conditions than their counterparts in Washington State, and the length of hospital stay was longer in the former group. After using logistic regression to adjust for patient differences, mortality rates for the 2 groups of patients with acute myocardial infarction were similar, although bypass surgery was used more frequently in patients in Washington State. For patients without myocardial infarction, hospital and 10-day mortality did not differ with respect to health care system, and the use of bypass surgery subsequent to angioplasty was similar. In the Department of Veterans Affairs, most hospitals had low institutional caseloads (< 150 procedures per year), whereas > 40% of Washington State hospitals performed > or = 300 procedures per year. Although there were greatly differing institutional caseloads, mortality and the need for early bypass surgery were similar in the 2 systems.