A sodium-layer laser guide star beacon with high-order adaptive optics al Lick Observatory (Mount Hamilton, California) produced a factor of 2.4 intensity increase and a factor of 2 decrease in full width at half maximum for an astronomical point source, compared with image motion compensation alone, The image full widths at half maximum were identical for laser and natural guide stars (0.3 are second). The Strehl ratio with the laser guide star was 65 percent of that with a natural guide star, This technique should allow ground-based telescopes to attain the diffraction limit, by correcting for atmospheric distortions.