Hospital and emergency department overcrowding is a serious and growing problem nationwide. Although EDs are organized around the goals of rapid patient assessment, stabilization, and prompt admission to the hospital, an increasing number are being required to hold admitted floor and critical care patients for extended periods due to lack of vacant inpatient beds. Provision of acceptable patient care under such circumstances requires a fundamental reordering of ED priorities and procedures. Overcrowding is the result of inadequate funding for emergency health care services during a period of increasing demand. The initial focus of management strategies to resolve this problem is the inpatient area and includes evaluation of length of stay, "intent to discharge" policies, flexible bed designations, restriction of in-house transfers, and the use of "over-census beds." If in-hospital management strategies fail, modifications in ED management may include staffing contingency plans, definition of physician responsibility, inpatient charts, revised pharmacy formulary, new floor plans, and modified accounting systems. Successful resolution of hospital and ED overcrowding may be the greatest challenge facing emergency medicine today.