A brief derivation of the equations for deformable dielectrics is presented. The basic theory generalises that due to Toupin , for it contains thermomechanical interactions and viscous dissipation within a non-equilibrium thermodynamic framework recently constructed by Bree and Beevers . Some asymptotic and Lyapounov stability results are established for initial-boundary value problems in the linearised theory using extended energy arguments. Similar arguments are then applied to produce analogous stability results for small electro-mechanical perturbations superimposed on a large static deformation and a strong magnetic field. © 1981 Martinus Nijhoff Publishers.