Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) ; Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) ; Processo FAPESP: 13/12642-7 ; Processo FAPESP: 10/16504-0 ; Processo FAPESP: 07/08534-3 ; PbZr1-xTixO3 (PZT) thin films (x = 0.46, 0.47, 0.48, 0.49, and 0.50) were deposited on Pt/TiO2/SiO2/Si substrates using a polymeric chemical method to study the effects of the composition on the macroscopic electrical and local piezoelectric properties. Both measurements demonstrate the existence of a self-polarization effect in all studied PZT films. The measurements were discussed in terms of the contribution of the Schottky barriers to the self-polarization effect. It is shown that both Schottky barrier effect and mechanical coupling near the film-substrate interface are not the dominant mechanisms responsible for the observed phenomena.