Experiments on the small angle scattering of thermal neutrons by powders are compared with theory. The available theories, which closely resemble those for small angle scattering of x-rays, are found to give a satisfactory account of the results. In general, the neutrons are scattered into a Gaussian distribution in angle whose width is directly proportional to the wave-length of the neutrons, the coherent scattering amplitude of the nuclei in the powder and the square root of the number of particles traversed in the powder by any one neutron.