Increasing human activity, industrialization, and a greater focus on globalization has largely impacted the environment and ecosystems. The rise in the usage of various chemicals and substances makes it even more imperative that the properties and potential of these chemicals to cause harm to humans and environment be deeply analysed. Risk assessment follows logical steps and uses data to predict and model the possible harmful effects of any particular substance. In this chapter, we have described various approaches that are taken in the process of carrying out an environmental risk assessment. We have also discussed the historical origins of risk assessment as well as analysed some of the tools and computer programs that are utilised in the process of risk assessment. Furthermore, some of the challenges that need to be addressed in the future in order to improve the accuracy of risk assessment even more and recommended approach have also been discussed.