Several recent incidents involving firefighter fatalities demonstrate that, despite technological advances in two-way radio communications, important information is not always adequately communicated on the fireground or emergency incident scene. Inadequate communication has a definite negative impact on the safety of emergency personnel and may contribute to injuries or deaths of firefighters, rescue workers, and civilians. Inadequate fireground communication is repeatedly cited as a contributing factor in many of the incidents reported through the United States Fire Administration Major Fires Investigation Project. This fact, coupled with the limited availability of research on such an important topic, prompted the United States Fire Administration (USFA) to study some of the potential causes of communication breakdown, and to provide recommendations that will help departments improve their operational communications. While the findings contained in this special report are primarily oriented toward the municipal fire service, this does not diminish their potential relevance to other firefighters and emergency responders. With respect to communicating in high-stress environments, numerous parallels exist across public safety and related disciplines. Some of the ideas presented here are drawn from the experiences of wildland firefighters, airline flight crews, and military personnel.