This chapter reviews the performance of membrane bioreactors (MBR) for the removal of pharmaceuticals from wastewater. Many factors affect pharmaceuticals removal by MBR. The factors include physicochemical characteristics of the pharmaceuticals and MBR operational parameters. The presence of a membrane allows various adsorption mechanisms for pharmaceuticals. Conceptually MBRs can deliver better removal of pharmaceuticals than conventional activated sludge (CAS) processes because of operation under longer solids retention times (SRTs), higher mixed liquor suspended solids (MLSS) concentrations, and complete retention of suspended solids. However, the available reports from lab and full-scale plants are sometimes conflicting. Further work is required to improve our understanding of the overall fate and degradation pathways of pharmaceuticals in MBRs.