The general problems of the evolution of wave surfaces and amplitudes associated with mechanical and electrical discontinuities in piezoelectric materials are dealt with in this paper. The results presented are relevant to shock waves propagating in all materials obeying the classical constitutive relations of piezoelectricity, including as a special case linear anisotropic elasticity. A specific example concerning BaTiO3 single crystal is considered. The example illustrates the intricate quantitative results which may be obtained as a consequence of the analyses.