In the event of a large-scale infectious disease outbreak, as could be seen with a bioterrorist attack, hospitals and their emergency departments would be on the front line. Federal, state, and local officials are concerned, however, that hospitals may not have the capacity to accept and treat a sudden, large increase in the number of patients, as might be seen in a bioterrorist attack. In the Public Health Improvement Act that was passed in 2000, Congress directed GAO to examine preparedness for a bioterrorist attack. In this report GAO provides information on the extent of bioterrorism preparedness among hospitals in urban areas in the United States. To conduct this work, GAO surveyed over 2,000 urban hospitals and about 73 percent provided responses addressing emergency preparedness. The survey collected information on hospital preparedness for bioterrorism, such as data on planning activities, staff training, and capacity for response. While most urban hospitals across the country reported participating in basic planning and coordination activities for bioterrorism response, they did not have the medical equipment to handle the number of patients that would be likely to result from a bioterrorist incident. Four out of five hospitals reported having a written emergency response plan addressing bioterrorism, but many plans omitted some key contacts, such as other laboratories. Almost all hospitals reported participating in a local, state, or regional interagency disaster preparedness committee. In addition, most hospitals reported having provided at least some training to their personnel on identification and diagnosis of disease caused by biological agents considered likely to be used in a bioterrorist attack, such as anthrax or botulism. In contrast, fewer than half of hospitals have conducted drills or exercises simulating response to a bioterrorist incident. Hospitals also reported that they lacked the medical equipment necessary for a large influx of patients. For example, if a large number of patients with severe respiratory problems associated with anthrax or botulism were to arrive at a hospital, a comparable number of ventilators would be required to treat them. Yet half of hospitals reported having fewer than six ventilators per 100 staffed beds. In general, larger hospitals reported more planning and training activities than smaller hospitals. Representatives from the American Hospital Association provided oral comments on a draft of this report, which GAO incorporated as appropriate. They generally agreed with the findings.