Abstract Lead zirconate titanate (PZT) ceramics with Zr/Ti ratios between 95/5 and 55/45 have been examined by transmission electron microscopy (TEM) and dielectric spectroscopy. It is believed that in the high Zr-content end of the PZT phase diagram that the relative phase stability is directly related to a coupling of the polarization to various oxygen octahedral rotational systems. The transformation between the high and low temperature rhombohedral ferroelectric phases (FER(HT)-FER(LT)) in PZT 90/10 was found to be associated with a transition between a high temperature M-type and a low temperature R-type oxygen rotational system. However, with increasing Ti-content (Zr/Ti<80/20) a transition between a disordered R-type tilted state to a low temperature ordered R-type tilted state was found near the FER(HT)-FER(LT) boundary. The transition between the disordered and ordered R-type tilted states became increasingly gradual with increased Ti-content. In the FER(LT) state, local strains due to random oct...