Study objectives: We characterize disaster preparedness among a cohort of hospitals, focusing on practice variation, plan characteristics, and surge capacity.Methods: This was a descriptive, cross-sectional study using an in-person hospital survey and a 117-item questionnaire in Los Angeles County, CA. The study included 45 of the 81 designated 911 receiving hospitals, including private and tertiary care facilities. Observations include a description of hospital disaster plans, modes of intra- and interhospital communication, community and interagency involvement, decontamination capability and training, drills, pharmaceutical stockpiles, and each facility's surge capacity (assessed by monthly emergency department [ED] diversion status, number of available beds, ventilators, and negative pressure isolation rooms). Additional measures of preparedness included whether hospitals had the following: mutual aid agreements with other hospitals, long-term care facilities, and medical vendors; protocols for canceling elective surgeries and early in-patient discharge; surveillance systems; ongoing training with local emergency medical services and fire departments; communication with the public health department; volunteer credentialing systems; and a protocol for mass fatality incidents.Results: Ninety-five percent had adopted the Hospital Emergency Incident Command System, and 100% used the ReddiNet, a radio-based communications network. Ninety-five percent had memoranda of understanding with medical suppliers. However, 67% never had joint training programs with local police and fire agencies, and only 16% and 7% had written mutual aid agreements with other hospitals and long-term care facilities, respectively. Eighty-eight percent of hospitals had level B and/or C personal protective equipment, and 44% had decontamination facilities suitable in inclement weather. Ninety-six percent of respondents noted a nurse shortage, 58% had a monthly ED diversion rate of greater than 20%, and 69% estimated a surge capacity of less than 20 beds. Fifty-eight percent of responding hospitals had fewer than 10 negative pressure isolation rooms, only 36% had more than 10 ventilators, and 55% did not keep a stockpile of antibiotics or antidotes. Although 93% and 98%, respectively, had protocols for canceling elective surgeries and early in-patient discharge, only 64% had plans in place for a mass fatality incident.Conclusion: There are no objective measures of “hospital preparedness” or “hospital surge capacity.” In addition to establishing such standards, focus must be placed on enhancing interagency and interhospital communications. Current numbers of available hospital beds, ventilators, isolation rooms, and pharmaceuticals may be insufficient to effectively care for victims of large-scale disasters and other public health emergencies.