Lead zirconate titanate [Pb(Zr0.53Ti0.47)O-3] films of thickness ranging from 70 to 680 nm have been prepared by the radio-frequency sputtering technique. The current density-electric field (J-E characteristics of the films were investigated. Films with thicknesses above 280 nm show a varistor-type J-E characteristic. This behavior is due to the presence of highly resistive grain boundaries and is termed a "grain boundary limited conduction mechanism". For films with thicknesses lower than 280 nm, trap-controlled space charge limited current is dominant. In this case, the dominance of the deep traps in the conduction mechanism has been confirmed from the temperature dependence of the J-E behavior