Passive films on zirconia were prepared by potentiodynamic polarization in the presence of a range of anions and at various pH values. With sulfate and chloride anions in the electrolyte we found unique transpassive peaks in the cyclic voltammograms that appear to be associated with an amorphous-to-crystalline transition and subsequent enhanced species transport along the resulting grain boundaries. X-ray photoelectron spectroscopy, secondary-ion-mass spectrometry, and ion-scattering spectrometry have been used to characterize the films before and after the passive film breakdown. The passive film breakdown can be qualitatively described by E-np = E-c + eta + Phi + E-inh Where E-np is the pitting potential, E-c the corrosion potential in acidified solution, eta the polarization necessary to obtain a current density high enough to maintain acidity inside the pit,Phi the potential drop inside of the pit, and Einh the contribution to the pitting potential resulting from inhibitors present. The results of these surface studies along with the variation in the cyclic voltammetry scans have been used to describe the process and to present a model that involves chemically bound water oxidation and local oxygen evolution. The effects of either Ohmic drop and/or local acidification are presented as well.