The increasing population and demand for resources have led to rapid urbanization globally. The aftermath of this is the arbitrary use of resources and services, with consequent enormous waste generation which has put the environment under undue and mounting stress. Improper management of various wastes can lead to disease transmission if not critically tackled. Wastewater from households and industries usually comprises diverse noxious substances that are not only dangerous to our environment but detrimental to the health of humans. Therefore, the treatment of wastewater before disposal is an important issue for safeguarding human health and in achieving environmental security. Several treatment methods for wastewater are adopted among which the biological treatment process is more proffered. Further research into the biological treatment method has validated the good use of microbes as the most sustainable and eco-friendly in the remediation of diverse (organic and inorganic) pollutants in wastewater systems. This present chapter therefore discusses the suitability of the microbial wastewater treatment method as the most effective and sustainable treatment method. We further reviewed the various advances in the microbial wastewater treatment process that confer the proven effectiveness and favor its continuous adoption.