In this paper we consider propagation of finite‐amplitude plane waves of uniaxial strain in piezoelectric disks exhibiting fully coupled nonlinear response. In particular, we derive explicit expressions for determination of the electric current in external circuits consisting of resistors, inductors, or capacitors connecting the electrodes on the faces of a disk. The formulation of a specific‐boundary initial‐value problem is discussed and a discussion of how the fully coupled electromechanical problem may be solved numerically is given.