Emergency and radiology department directors at 517 acute-care US teaching hospitals were sent identical questionnaires surveying practice patterns of ED plain film radiograph interpretation. Fifty-seven percent of ED directors and 51% of radiology department (RD) directors responded. Both groups reported that the most common practice pattern (60%) was alternating responsibility for immediate interpretation between emergency physicians and radiologists during a 168-hour week. Remaining hospitals were nearly equally divided between systems in which radiologists always provided immediate interpretation and those in which the emergency physicians always provided the initial interpretation. In all systems in which emergency physicians provided some immediate radiograph interpretation, radiologists provided subsequent review. Institutions varied as to the level of training of the physician in both the ED and RD who provided immediate radiograph interpretation; at least 30% of the institutions responding were reported to have either emergency physicians or radiologists of resident level providing immediate interpretation at least part of the 24-hour day. Interpretation discrepancy rates between emergency physicians and radiologists were estimated to be 4% to 6%. The large amount of variation among hospitals in ED radiograph interpretation systems suggests that these systems were not designed with quality of care concerns as their primary criterion. As a consequence, objective patient outcome and process measures need to be developed and measured to ensure that a particular internal system for ED radiograph interpretation is providing an acceptably high standard of patient care.