Although some things have not changed much since Merrill Sosman's time, many ethical and economic aspects of medical practice are now being scrutinized much more closely than in the past. Among the questions being asked are the following: Are physicians overutilizing technology? How much and by what criteria are physicians being paid (or overpaid)? Is the best possible quality of care being provided to patients? During the past few years, several colleagues and I have worked with a group at Pennsylvania Blue Shield (PBS) to study utilization, cost, and quality issues associated with the practice of radiology by nonradiologists. Compelling data and concepts have emerged from these studies. This article reviews some of our findings and other issues in three areas: (1) utilization patterns and costs for outpatient radiographic, sonographic, CT, and MR imaging examinations of PBS subscribers throughout the state during 1991; (2) recent trends in the utilization of barium enemas, colonoscopy, and percutaneous transluminal coronary angioplasty (PTCA); and (3) comparison of the quality of radiographic examinations performed by radiologists and nonradiologists. Although these subjects are somewhat disparate, they all bear on the three health policy questions posed above. They also relate to the landmark studies of Hillman et al. [1, 2], who demonstrated that self-referring nonradiologist physicians who perform their own radiographic and sonographic studies perform two to eight times as many of these studies as do other physicians who instead refer their patients to radiologists.