Maghemite nanoparticles (γ-Fe2O3) were successfully synthesized by co-precipitation method as to remove toluene from sea water. The obtained sample was characterized with X-ray diffraction and transmission electron microscopy which showed that the size of particles was in the average of 9 nm. Further, Fourier transform infrared spectroscopy was performed to ensure successful coating process. The influence of other physico–chemical parameters such sunlight, initial toluene concentrations (5, 10, and 15% V/V), and equilibrium contact time (120 min) were also studied. The results showed that 90% of toluene could be removed within a period of 120 min and the toluene solution with initial concentration of 5 mg/L has shown to have the best removal efficiency