The effect of air shear on the development of a thin conducting fluid film on a rough rotating disk has been analysed. A uniform magnetic field acts parallel to the axis of the rough rotating disk. The numerical solution of the governing equations of motion using the initial and boundary conditions have been obtained by a finite difference method. The effect of air shear on the temporal evolution of the free surface of the fluid and on the retention of the liquid lubricant has been analysed. © WILEY-VCH Verlag Berlin GmbH.