The primary aim of disaster response is to restore order, support damaged or nonfunctioning societal functions, and, shortly afterward, reconstruct and rehabilitate the affected society to, at minimum, its predisaster situation. There are three vital phases of the disaster response: preparedness, response, and recovery. Preparedness includes the assessment of risks in relation to material and personnel resources, efficient planning, medical response tactics, and continual training of the staff, including a sufficient amount of field exercise involving various rescue teams. Medical response includes standardization of approach, terminology, communication, and command. Medical response also includes triage of patients and treatment as appropriate for their safe transport for more complete treatment in hospitals. The recovery phase is the prolonged period of adjustment or return to equilibrium that the community and individuals must go through. Evaluation of a disaster begins by reviewing the response plan and its measurable objectives. In the process of conducting an evaluation, assessments are directed for five domains of activity: structure, process, outcomes, response adequacy, and costs. There is a role for each specialist in the management and response to disasters, including surgeons, anesthesiologists, nurses, pediatricians, and psychiatrics. This chapter reviews the general characteristics and phases of large-scale disasters, medical response, and the role of some specialists in that response.