Pressure to lower the cost of health care delivery has fostered widespread efforts to limit patients' access to specialists such as cardiologists. However, there is concern that diminished specialist involvement may lead to poorer patient outcomes for specific clinical conditions. As part of a state-sponsored effort to improve the quality of health care in Pennsylvania, the Pennsylvania Health Care Cost Containment Council gathered clinical and administrative data on all 40,684 hospital admissions for acute myocardial infarction (AMI) in that state in 1993. They prepared a detailed public report that included risk-adjusted in-hospital mortality and length of hospital stay by physician group, by hospital and by region. These data demonstrate that patients cared for by cardiologists, as a group, had a lower risk-adjusted mortality than patients cared for by either internists (risk ratio 1.26, 95% confidence interval 1.17 to 1.35) or family practitioners (risk ratio 1.29, 95% confidence interval 1.18 to 1.40). The patients of cardiologists also had a shorter length of stay than the other two groups. These data suggest that there is enhanced value in the care provided by cardiologists for patients with AMI and call into question the growing trend toward reliance on generalists instead of specialists.