Stresses suffered by lead zirconate titanate (PZT) components in actuators are the origin of the gradual degradation of the microstructure and piezoelectric capability that limits their lifetime. The stress-strain behavior of a PZT ceramic has been studied in compressive uniaxial cyclic loading using a constant loading rate, in order to determine the operating stresses that cause structural damage associated to the exhaustion of twinning. Domain switching strain curves have been calculated considering that stress-induced switching of 90 o domains is the mechanism responsible of non-linear stress-strain behavior. Each load-unload cycle caused a permanent strain in the PZT. Successive cycles produced incremental increases in stress-induced permanent strain, up to a maximum value or 'saturated cyclic permanent strain', attributed to irreversible stress-induced domain switching. The dependence of the saturated permanent strain with the maximum cyclic load showed a characteristic non-linear behavior, with a steep slope at a stress level σ I , that we called the 'critical stress for irreversible domain switching'. Below σ I , the majority of domain switching is reversible. We have called σ R to the stress at which the increase in reversible domain switching is more pronounced. At stresses between σ R and σ I high reversible strains can be reached without resulting in permanent stress-induced depoling and thus without the exhaustion of available twinning during subsequent load cycles. At maximum cyclic stresses higher than σ I , irreversible domain switching accounts for the majority of strain and increase rapidly toward values close to the maximum 90 o domain switching strain available. The number of cycles to failure also had a strong dependence with the maximum cyclic stress. Cyclic stresses above the critical stress caused a rapid accumulation of permanent strains, so the saturated value is reached after a few cycles, resulting in early catastrophic failure, because of the exhaustion of reversible domain switching.