In the present study, Zn-doped cobalt ferrite (CoFe1.9Zn0.1O4) magnetic nanoparticles were successfully synthesized via sol-gel method. The prepared materials were characterized using X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The apparent density and magnetic force of CoFe1.9Zn0.1O4 nanoparticles were determined. The results revealed that the prepared materials display an adequate density and considerable magnetic force. The gravimetric oil removal capability tests were also performed to investigate the oil absorption properties of CoFe1.9Zn0.1O4 nanoparticles using four types of oil samples (crude, diesel, gasoline and hydraulic oil) as water pollutant's model. The oil removal capabilities of the prepared absorbent were found to be 13.72 ± 0.42-5.50 ± 0.53 g/g, 14.99 ± 0.95-8.86 ± 0.42 g/g, 18.23 ± 1.01-8.06 ± 1.26 g/g and 10.58 ± 0.49-5.24 ± 0.31 g/g for crude, diesel engine, gasoline engine and hydraulic oil, respectively. The results suggest that the prepared magnetic nanoparticles can be used as absorbent materials for removing oil spills from water surface. Magnetic nanomaterials Spinel ferrite nanoparticles Oil spills Gravimetric oil removal