AbstractA magnetic resin based on lignin produced using the Kraft process was prepared and characterized. The material, because of its aromatic/aliphatic balance, can be used in oil‐spill clean‐up processes. The resin was prepared through bulk polycondensation of lignin, cashew nutshell liquid, and formaldehyde in the presence of maghemite nanoparticles. The obtained magnetic composites were studied by Fourier transform infrared spectroscopy, X‐ray diffraction, and Small‐angle X‐ray scattering. Cure degree, magnetic force, and oil removal capability tests were also performed. The results show that the composites possess an elevated cure degree, besides a considerable magnetic force. The materials exhibit a good oil removal capability—the composite containing 3.3 vol % of maghemite can remove 11 parts of oil from water. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012