The dissolved fractions of polycyclic aromatic hydrocarbons (PAHs) in wastewater have many adverse effects on humans, animals, and water species. The objective of this study is to study the removal of PAHs in produced water (PW) using oil palm leaves activated carbon (OPLAC). The OPLAC was applied for the degradation of naphthalene (NAP), one of the commonly found PAH, in aquatic solution and PW at various pH (3�9), dosage (100�3000 mg/L) and contact time (5�90 min). The parameters were optimized using response surface methodology (RSM). The optimum parameters were as follows: pH of 3, dosage of 2197 mg/L and contact time of 72 min giving removal efficiency of 92.48 in aquatic solution. The results were verified in the laboratory. The removal efficiency of NAP from PW sample was 70.5 at optimized parameters. It was closer to the experimental results with 19 difference. © 2024, Institute of Technology PETRONAS Sdn Bhd.