Magnetically responsive nanofiltration membranes have been developed by attaching a superparamagnetic nanoparticle to the end of polymer chains grafted from the surface of commercially available nanofiltration membranes. In an oscillating magnetic field, movement of these magnetically responsive polymer chains leads to break up of the concentration polarization at boundary layer. Experiments using feed streams consisting of an organic salt, an inorganic salt, as well as a synthetic oily wastewater have been conducted for periods of up to 6 h in order to determine the effect on long term membrane fouling. The results indicate suppression of long term fouling in the presence of an oscillating magnetic field.