A core principle of planning and managing security for major special events is that timely, effective planning; communication; and training are critical. Other principles that law enforcement administrators emphasized during the study were as follows: plan for worst-case scenarios; weigh the security measures that could be taken against the desire to keep intrusiveness and restrictions to a minimum based on risk assessment; establish new but temporary management and communication structures deemed appropriate for the event; respect constitutional rights of event attendees; develop an interoperable communications capability if multiple agencies are involved; involve appropriate community organizations and leaders in planning; and build event security training into basic and inservice training. Specific advice is provided for pre-event planning, managing security during the event, and postevent activities. The article also outlines the responsibilities of the executive team, which is created as the first step in security planning for a major event. Other issues discussed are agreements with other agencies; threat and risk assessment (vulnerability of information systems and business impact analysis); and communications and communication technology (communications command center and radio communications). Major sections of the article contain recommendations for radio communications protocol at special events, personnel and training, and management during and after the event.