Bioremediation involves the application of micro-organisms for the removal of contaminants from the environment. Bioremediation competes effectively with other remediation approaches, such as thermal desorption and incineration. Further innovation of this technology involves the development of geneticically engineered strains with enhanced biodegradability capabilities. At present, however, there have been very few reported examples where genetically engineered micro-organisms have been released into commercial bioremediations. The main reasons for this include the lack of knowledge of the environmental risks and benefits of releasing genetically modified organisms into a contaminated area. In addition, non-specialist stakeholder support is often overlooked and remains a crucial area for improvement if sustainable remediation is to continue to develop. This chapter focuses on the application and risks associated with bioremediation.