Microbial fuel cells (MFCs) are emerging as a versatile renewable energy technology. This is particularly because of themultidimensional applications of this eco-friendly technology. The technology depends on the electroactive bacteria,popularly known as exoelectrogens, to simultaneously produce electric power and treat wastewater. Electrodemodiﬁcations with nanomaterials such as gold nanoparticles and iron oxide nanoparticles or pretreatment methods suchas sonication and autoclave sterilization have shown promising results in enhancing MFC performance for electricitygeneration and wastewater treatment. The MFC technology has been also investigated for the removal of various heavymetals and toxic elements, and to detect the presence of toxic elements in wastewater. In addition, the MFCs can bemodiﬁed into microbial electrolysis cells to generate hydrogen energy from various organic matters. This article providesa comprehensive and state-of-the-art review of possible applications of the MFC technology. This also points out thevarious challenges that limit MFC performance. Finally, this article identi ﬁes the strategies to improve MFC performancefor different applications.