This chapter describes various approaches to recognizing and preventing occupational and environmental disease and injury from primarily a clinical perspective. It describes in detail the occupational and environmental health history, including what questions to ask and when to ask them. It also describes recognizing occupational or environmental disease clusters or outbreaks. The chapter describes in detail the options that health and safety professionals have for implementing and facilitating preventive measures, including substitution of hazardous substances, installation of engineering controls, changes in job design and work practices and organization, education and training, use of personal protective equipment, and screening surveillance. Prevention options are discussed both at the individual and organizational levels.