Ferroelectric Pb(Zr(60)Ti(40))O(3) ceramics sintered for 6 hours at 1050 degreesC in air and doped with La or Nb in the range 0.5 to 6 mol% have been investigated by positron lifetime spectroscopy and two-dimensional coincident Doppler measurements. The undoped samples show two lifetime components with a defect lifetime of about 250 ps. After doping this defect lifetime increases to about 295 ps. The influence of the doping on the Doppler spectra is extremely small. Additional XRD pattern show a significant correlation between doping and lattice structure.