This chapter discusses hazard, risk, and crisis communication within the context of biorisk management. Several main aspects exist when delivering hazard, risk, and crisis communication: the type of information communicated, the urgency of the communication, and the media used for the communication. Communication goals should be identified based on the audience, the content of the message, and the nature of the hazard, risk, or crisis. There may be multiple audiences with differing information needs for the different types of message (hazard, risk, or crisis). The messages should be created to address the different audiences’ needs and how well the audience understands the hazard, risk, or crisis that needs to be communicated. Many audiences will internalize the information subjectively, and if their particular concerns are not addressed in the message, they may presume a worstcase scenario even when presented with complete information. Failure by institutions to incorporate value judgments into communication about hazards, risks, and crises can distract from and skew the message’s original intent-which could range from threshold hazardous biological substance reporting to a full-scale alert in the event of a dangerous release. Including the public as a target audience and a source of biorisk management information, such as information on threats for assessment purposes or contamination for performance measures, is often overlooked during the risk assessment process. Biorisk management systems should incorporate a structured communication process to discuss and evaluate hazards, risks, and crises to mitigate consequences of negative public perception of the risk that the facility and the hazards contained therein pose to the community.