A noncontact, nondestructive, laser‐based method for remote monitoring of material grain size is described. A surface acoustic wave surge, generated in the material under test by a short, high‐power laser pulse, is detected optically. The leading‐edge rise time of the acoustic signal is found to relate to the material grain size through frequency‐dependent scattering. In assuming a Rayleigh scattering model, a good correlation with metallurgical measurements is obtained in steel specimens.