The linear stability of radial flow of a viscous fluid in the presence of a radial magnetic field is investigated. Basic velocity field q 0 = (c/r,0,W) and magnetic field B 0 = (A/r,0,0) are considered in an annulus between two concentric cylinders. To analyze hydro-magnetic stability, inner product method is employed. The stability condition derived is found to remain valid even when the local velocity is not entirely radial, and that the magnetic field exerts a stabilizing effect on the flow.