The palm oil mill effluent imposes environmental issues because of natural and supplement substance. This waste has a significant amount of biological oxygen demand, total suspended solids, chemical oxygen demand, and turbidity. Moringa oleifera seeds� performance analysis as natural coagulants during the pretreatment stage of palm oil mill effluent before it is filtered through commercial nanofiltration membrane is the focus of the current study. The untreated palm oil mill effluent has 2,410 mg/L biological oxygen demand, 3,900 mg/L chemical oxygen demand, 865 NTU turbidity, 41,900 mg/L total suspended solids, and 4.61 pH. The significant reduction occurred in the feed parameters viz., 91.7 for biological oxygen demand, 83.0 for chemical oxygen demand, 67.7 for total dissolved solids, and 72.8 for turbidity after the pretreatment; however, the pH increased to 4.88. Design expert® was used to design the experiments and optimize the palm oil mill effluent pretreatment process via a one-factor experimental design. The optimized solution has a 0.994 desirability index. Finally, it was concluded that with ever-tightening environmental standards, moringa oleifera could provide a cheap, green, and potential natural alternative to the existing coagulants employed to treat the palm oil mill effluent. © 2021 Wiley-VCH GmbH