Anthropogenic activities have aggravated the problem of environmental contamination globally. The currently used physicochemical methods have limitation requiring the search for environment-friendly options for contaminant removal from a system. Application of microbes, especially diverse bacterial species, is attractive because of their fast growth and easy adaptation even under harsh environmental conditions. Many of the xenobiotic compounds are either nonbiodegradable or slowly degradable by microbial communities. Because the indigenous bacteria are less efficient in degrading the pollutants, designing of engineered bacterial systems for enhanced degradation of hazardous contaminants could serve as a suitable approach for mitigating the impacts of pollutants on environment and human health. However, the release of transgenic bacteria for field application to clean the noxious contaminants is a matter of controversy. The release of engineered bacteria may affect the natural microbial diversity, and the genes for catabolism of a particular substance may be harbored by pathogenic microbes. Lots of research has been performed to detect the presence of transgenic bacteria under environmental conditions along with the development of suicidal genetically engineered microbes to restrict their transfer into native microorganisms. Hence, the use of genetically engineered bacteria could serve as a viable option for management of contaminated sites.