<p>The increasing discharge of azo dyes is of ecological concern due to its toxicity and resistance to conventional treatment methods. Microbial fuel cell (MFC) technology has long been identified as a potential solution for treating recalcitrant waste, such as azo dye effluents, providing a dual advantage of dye degradation and energy recovery. This review elucidates azo dye structure, chemistry and its influence on the degradation in MFC with emphasis on redox transformations at the electrodes. At the anode, azo bond reduction with the help of microbial catalysts produces aromatic amines. At the cathode, azo dye can be the terminal electron acceptor, leading to dye decolorization, or it can be degraded to smaller intermediates in an advanced oxidation process. The anodic dye degradation, electrode materials, microbial catalyst, co-substrate, degradation at biotic/abiotic cathode and various membranes used in MFCs have been summarized. The integration of nanomaterials into MFC components for improving electron transfer rates, reducing electrode overpotentials, facilitating electrode-microbes interaction and enhancing membrane cation transfer has been discussed. The recent advancement in scaling up of MFC for dye treatment by integrating with other treatment systems and stacking individual MFCs has been outlined. The review concludes with a future perspective on advancing scalable MFC by consolidating research insights on MFC materials, microbial interactions, reactor design and operational parameters to realize real-world applications.</p> Graphical abstract <p></p>