Bulk laser damage threshold of 2‐in.‐diam. MgO‐doped LiNbO3crystals grown using the Czochralski technique has been measured using aQ‐switched Nd3+:LiYF4laser. The threshold showed dependence on the crystal quality. The highest bulk laser damage threshold (14 J/cm2at 1.053 &mgr;m wavelength with 1‐ns pulse width) was obtained in the LiNbO3crystal doped with 1 mol % of MgO. The lowering of bulk laser damage threshold was observed in the crystals doped with MgO at more than 3 mol %. These crystals contained the local aggregations of MgO which increased the scattering centers and decreased the transparency.