A novel trimetallic W-Mg-Al oxide composites immobilised onto starch were synthesized via sol-gel method. W-Mg-Al oxide composites were synthesized by first preparing WO₃ using incipient wetness method, followed by immobilising onto MgO-Al₂O₃ support using starch as binder. The effects of starch addition on the crystal properties and morphology were investigated by X-ray diffraction (XRD), Fourier Transform Infrared (FT-IR) spectroscopy and Scanning Electron Microscopy (SEM). In the presence of hydrogen peroxide and acetic acid as oxidant system, W-Mg-Al oxide starch composites exhibited higher catalytic performances for oxidative desulphurisation (ODS) of dibenzothiophene (DBT) at 95% compared to W-Mg-Al oxide composites. The catalytic activity observed could be correlated to the distribution of active phases on starch as well as the higher crystallinity of the metal oxide composites.