The dielectric and piezoelectric response of PZT-5H ceramics at high electrical and mechanical loads is presented. The purpose of this study is to provide a detailed explanation of the effect of prestress on the induced polarization and strain. The material is electrically cycled (−2/+2 MV/m, 0/+2 MV/m, and −0.4/+2 MV/m) at constant mechanical prestress levels up to 175 MPa. A descriptive model is used to explain the results in terms of consecutive non-180° domain wall motion only. The response of the material depends on the non-180° domain wall motion produced by the balance between the applied electric field and prestress. The limitation of the model is that it neglects 0° and 180° domains contribution to the response of the actual material.