OBJECTIVE: National security special events occur yearly in the United States. These events require comprehensive advance planning for health and medical contingencies in addition to law enforcement concerns. The planning for and impact of the Republican National Convention (RNC) on the City of St Paul and the Minneapolis-St Paul metropolitan area is described. METHODS: Descriptive analysis of events was provided by the authors based on their planning and operational experiences. Daily data were gathered from area hospitals, emergency medical services agencies, the National Weather Service, federal medical teams, and the Minnesota Department of Health to capture the impact of the RNC on emergency department activity, nonemergency surgery, emergency medical services run volumes, patient visits to onsite and offsite medical clinics, and general hospital occupancy in the metropolitan area. RESULTS: There were no epidemiological signal events. Weather was not extreme. Confrontations between protestors and law enforcement resulted in frequent use of riot-control agents. Protestors sought medical care from "street medics" and their affiliated free clinics in preference to usual medical facilities. Emergency departments close to the event venue reported decreased patient volumes. Hospitals close to the venue reported significantly decreased nonemergency surgical case volumes. Local hospitals implemented access controls and in 1 case, shut down ventilation systems due to riot-control agent deployment in the streets outside. Emergency medical services volumes were near average, with the exception of St Paul Fire Department on the day of a major protest march. CONCLUSIONS: Planning and operational response for the RNC consumed large amounts of time and resources. The RNC had minimal patient impact on the health care system and in fact caused significant volume decreases at hospitals proximate to the venue. Although contingencies available for a mass casualty event were not needed, they must continue to be available for all such events. Health and medical preparedness and funding is not adequately detailed in the planning framework for national security special events, and this should be a focus for future events.