The intent of this chapter is to define the goal of a risk assessment, and to explain in general terms how to conduct a risk assessment. This chapter also provides some concepts to consider when determining whether or not to accept some level of risk, and how to ensure that a risk assessment fits into a biorisk management system. The purpose of this chapter is not to serve as a detailed technical manual on biological risk assessment; rather, it provides the reader with the basic guidance required to understand and value a structured risk assessment approach.