The laser-power-handling properties of planar out-diffused and in-diffused lithium niobate waveguides are considered in terms of fabrication process characteristics. The percentage of laser induced power-loss is found to increase as the square of both the input-coupled laser power and the beam's transmission distance in the guide, regardless of the fabrication details. Titanium in-diffused waveguides are found not to exhibit laser-induced power-loss for beams proloaaatina along their z-axis.