Studies of high optical power density propagation in Ti‐diffused LiTaO3waveguides are described. Optical damage at room temperature involving ’’blow‐out’’ of the central output spot into themline and clean‐up phenomena have been observed. Studies at elevated temperature (≈150 °C) indicate that self‐annealing of the damage allows these structures to sustain optical power densities up to 11 kW/cm2at 5145 A˚ without damage and power saturation. Use of high‐purity LiTaO3is required if room‐temperature operation at these high optical power densities is to be achieved.