The effects of Bi(Zn0.5Ti0.5)O-3 (BZT) substitution in BaTiO3 (BT) or (Bi0.5Na0.5) TiO3 (BNT) piezoelectric ceramics were studied. (1-x) BaTiO3 - xBi(Zn0.5Ti0.5)O-3 (x = 0.02, 0.04, 0.06, 0.08, 0.10, 0.20, 0.30, and 0.40) and (1-y)(Bi0.5Na0.5)TiO3 - yBi(Zn0.5Ti0.5)O-3 (y = 0, 0.01, 0.025, 0.05, 0.10, and 0.20) ceramics were prepared by a solid state reaction method. The structures and surface morphologies have been examined using an X-ray diffraction and scanning electron microscopy, respectively. The grain size and density increased with increasing the amount of BZT in both systems. Curie temperatures (T-C) were decreased as BZT substituted. Piezoelectric properties also decreased with the substitution of BZT.