The presence of microplastics (MPs) in wastewater has significant impacts on various aspects of the wastewater treatment process. Traditional treatment plants are not equipped to remove MPs, resulting in daily discharge into the environment. Membrane bioreactor (MBR) processes have emerged as a promising strategy for removing MPs, with high removal rates seen in both real and pilot-scale wastewater treatment plants. However, the accumulation of MPs in MBRs significantly affects pollutant removal efficiency, while their presence can decrease membrane fouling due to their scouring effect. The impact of MPs on MBR systems and their microbial communities is complex and influenced by various factors, including the type and concentration of MPs, the microbial community's composition and activity, and the MBR system's operational parameters. Additional studies are necessary to evaluate the effects of different MP types and sizes on membrane fouling in real-world situations, and steps should be taken to address any negative consequences. Overall, comprehending the impact of MPs on MBR systems is critical to optimize wastewater treatment and minimizing MPs discharge into the environment.