The effect of niobium doping on the structure and properties of piezoelectric PZT ceramics is studied. Samples of the system Pb(Zr0.54Ti0.46)O-3 + x wt % Nb2O5, (x = 0.2, 0.4, 0.6, 0.8, 1.0) were obtained by calcination of mixed oxides and subsequent sintering. Structural analysis (XRD and Optical Microscopy) was carried out. All compositions lead to single-phase tetragonal samples. As a general tendency, grain size and porosity decrease as the niobium concentration increases. Important fiber texture appeared in all samples, with crystallite [001] direction parallel to sample symmetry axes. Texture becomes more intense as the Nb concentration increases. Studying the polarization and the piezoelectric constant d(33), we observe a maximum of these properties for the intermediate value x = 0.8.