Magnetorheology (MR) is a technology to enable active control of the viscosity of a material - typically afluid, but also semi-solid materials such as lubricating greases. Magnetic particles of nano to micron scale aremixed with the fluid and when subjected to a magnetic field the particles are aligned with the field, inducing ashear resistance - i.e. the effect of an increased viscosity - if applied in appropriate direction. This technology isfor example used in active dampers in sports cars, where electromagnets activated by a sensor systemcontrols the viscosity of the damper oil and the pressure in the dampers. This paper proposes a method ofusing MR technology to reduce wear in wind turbine bearings by enhancing the lubricant film in the maximumHertzian contact. Electromagnets are used to control the sequence of demagnetization and magnetization ofthe lubricant. Here the wear particles existing in the lubricant acts as guiding particles.