We report on anisotropic wave mixing in planar iron-doped titanium-indiffused LiTaO3 waveguides. The diffusion of titanium in Y-cut LiTaO3 is investigated for different temperatures and diffusion times, yielding the diffusion constant. Material properties of the waveguides such as conductivity and nondiagonal photovoltaic tensor elements are investigated by two-wave mixing of orthogonally polarized modes. Phase conjugation in waveguides by anisotropic four-wave mixing is demonstrated, too, and experimental results are compared with numerical solutions of the corresponding system of coupled-wave equations.11917361742