The scatter in phase which occurs when a beam of ultrasonic radiation transverses polycrystalline medium is here treated as a stochastic process. This approach leads to an attenuation from polycrystalline scattering proportional to the grain size divided by the square of the wave‐length. Whereas prior treatments of this subject are valid for the wave‐lengths either much smaller or much larger than the grain size, the method used here holds best over the intermediate frequency range.