The fatigue processes caused by repeated cyclic switching of polarization in lead titanate and lead zirconate titanate thin films on silicon substrates by applying rectangular pulse and sine wave fields are investigated. Upon an increase in the cycling number, an increase in the coercive and internal bias fields is observed, along with a reduction in the switching current maximum, the switching time, and the switchable polarization. At the same time, no change in the mobility of domain boundaries is observed.