A novel nanomagnetic organogel was synthesized by in situ emulsion polymerization-crosslinking method using dodecyl methacrylate (DDMA) and styrene (St) as monomers, divinylbenzene (DVB) as a crosslinking agent, azobisisobutyronitrile (AIBN) as an initiator, and Fe3O4 as a nanomagnetic particle. Modification of the network was carried out by inclusion of the multi-walled carbon nanotubes (MWCNT) into the organogel matrix. The structure of the nanocomposite was characterized using FTIR spectroscopy, SEM, TEM, TGA/DTG, VSM, and BET analysis. The effects of various parameters such as the amount of crosslinker, initiator, Fe3O4, and reaction time as well as monomer ratio on the oil absorption of the organogel were studied. The synthesized organogel can absorb about 35.5, 22.1, 29.86, 14.58, 17.6, 15.3, and 13.7 g·g-1 of CHCl3, toluene, CH2Cl2, hexane, crude oil, gasoline, and diesel oil, under the optimized polymerization conditions, respectively. The nanocomposite organogels can be easily separated by a magnetic field after absorption of organic solvents.