This chapter presents the study on pollutant removal in palm oil mill effluent using chitosan as natural coagulant. Up until today, palm oil mill effluent (POME) considered one of the significant sources of environmental pollution. The characteristics of POME include contaminating the source of drinking water, which also harmful to the aquatic ecosystem by creating a highly acidic environment or causing eutrophication. With increasing public awareness of environmental pollution, it creates the need to address this issue. Chitosan is non-polluting food-based anionic and biodegradable biopolymer that are environmentally friendly useful in wastewater treatment. The critical parameter to determine the effectiveness of pollutants removal is chemical oxygen demand, color, and total suspended solids. This chapter also presents and discusses some of the significant findings to provide proper understandings and implications in this topic.