After Hurricane Katrina struck the Gulf Coast of the United States on 29 August 2005, it became obvious that the country was facing an enormous national emergency. With local resources overwhelmed, governors across the US responded by deploying thousands of National Guard soldiers and airmen. The National Guard has responded to domestic disasters due to natural hazards since its inception, but an event with the magnitude of Hurricane Katrina was unprecedented. The deployment of >900 Army National Guard soldiers to St. Bernard Parish, Louisiana in the aftermath of the Hurricane was studied to present some of the operational issues involved with providing medical support for this type of operation. In doing so, the authors attempt to address some of the larger issues of how the National Guard can be incor- porated into domestic disaster response efforts. A number of unforeseen issues with regards to medical operations, medical supply, communication, preventive medicine, legal issues, and interactions with civilians were encoun- tered and are reviewed. A better understanding of the National Guard and how it can be utilized more effectively in future disaster response operations can be developed.