PLZT {lanthanum doped PZT [Pb(Zr-0.52, Ti-0.48)O-3} thin films with 5, 8 and 10 mol% lanthanum were processed via chemical solution deposition on (111)-Pt/TiO2/SiO2/Si (100) and LaNiO2 (LNO)/(111)-Pt/TiO2/SiO2/Si (100). The thin films were investigated in terms of the influence of lanthanum content and substrate heterolayer structure on the microstructure and dielectric properties. It is shown that deposition on (111)-Pt leads to a (100)/(111) preferred texture and a coarse grained microstructure with PbO depleted areas. Deposition on LNO results in a randomly oriented, fine grained microstructure. The dielectric constants decrease with increasing lanthanum content and are higher for the films deposited on Pt. They take values between 1630 (0.05 mol La3+) and 865 (0.1 moI La3+) for deposition on Pt and between 1090 and 808 for deposition on LNO. The fatigue properties depend also on the lanthanum content and substrate type. The PLZT thin films with lanthanum concentration above 0.05 deposited on LNO show no fatigue.