Palm and coconut shells are among the most common feed materials for activated carbon manufacturing. Activated carbon is an excellent adsorbent for palm oil mill effluent (POME), especially for the removal of chemical oxygen demand (COD). Palm shell-based activated carbon (PAC) and coconut shell-based activated carbon (CAC) have been prepared through carbonization and followed by an activation process using H2SO4 2.5 M. Both PAC and CAC have lower contents of moisture, fly ash, and ash than that of Indonesian national standard thresholds. The COD removal from POME was performed with the batch adsorption method, where it reached adsorption saturation after 45 minutes of stirring time and optimum removal at pH 3. Isotherm studies suggest that the COD removal using PAC and CAC fit the theoretical data from the Langmuir isotherm model (R2 > 0.99) with Qm of 854.701 and 826.446 mg/g, respectively. The investigation also indicates that PAC has a better performance in COD removal, which has been justified by the elucidation using Fourier Transform-Infrared (FT-IR) and Scanning Electron Microscopy – Electron Dispersive Spectroscopy (SEM-EDS) technique.