Strong community linkages are essential to a health care organization's overall preparedness for emergencies. To assess community emergency preparedness linkages among hospitals, public health officials, and first responders and to investigate the influence of community hazards, previous preparation for an event requiring national security oversight, and experience responding to actual disasters. With expert advice from an advisory panel, a mailed questionnaire was used to assess linkage issues related to training and drills, equipment, surveillance, laboratory testing, surge capacity, incident management, and communication. A simple random sample of 1750 U.S. medical-surgical hospitals. Of 678 hospital representatives that agreed to participate, 575 (33%) completed the questionnaire in early 2004. Respondents were hospital personnel responsible for environmental safety, emergency management, infection control, administration, emergency services, and security. Prevalence and breadth of participation in community-wide planning; examination of 17 basic elements in a weighted analysis. In a weighted analysis, most hospitals (88.2% [95% CI, 84.1% to 92.3%]) engaged in community-wide drills and exercises, and most (82.2% [CI, 77.8% to 86.5%]) conducted a collaborative threat and vulnerability analysis with community responders. Of all respondents, 57.3% (CI, 52.1% to 62.5%) reported that their community plans addressed the hospital's need for additional supplies and equipment, and 73.0% (CI, 68.1% to 77.9%) reported that decontamination capacity needs were addressed. Fewer reported a direct link to the Health Alert Network (54.4% [CI, 49.3% to 59.5%]) and around-the-clock access to a live voice from a public health department (40.0% [CI, 35.0% to 45.0%]). Performance on many of 17 basic elements was better in large and urban hospitals and was associated with a high number of perceived hazards, previous national security event preparation, and experience in actual response. Responses reflect hospitals' self-perception of linkages. The quality of linkages and the extent of possible biases favoring positive responses were not assessed. In this baseline assessment, most hospitals reported substantial integration. However, results suggest that relationships between hospitals, public health departments, and other critical response entities are not adequately robust. Suggestions for enhancing linkages are discussed.