Raw palm oil mill effluent (POME) contains high amount of organic materials and residual oil that will impose high biological oxygen demand (BOD) and chemical oxygen demand (COD). It has a high acidic value, high total suspended solids (TSS) and is dark brownish in colour. Raw POME is a highly polluting wastewater and as such, it cannot be freely and/or directly discharged into any source of water or river without prior proper treatment. The treatment of raw POME is an important issue in palm oil mills and the method of treatment has attracted many researchers and non-governmental organisation (NGO) associated with environmental pollution. Owing to the more stringent effluent environmental regulations by the Department of Environment (DOE) Malaysia, research interest has recently shifted to the development of sustainable effluent polishing technologies. Therefore, it is perhaps worthwhile to look into a new viable and sustainable technology such as utilisation of renewable oil palm biomass as bio-adsorbents. This article reviews the development of polishing treatments for POME final discharge and further discusses the application of palm-based activated carbon for the treatment system. In conclusion, the integration system of conventional POME treatment with bio-adsorbents could be considered as a sustainable approach, thus solving environmental problems of waste disposal and pollution control for the oil palm industry.