The material or object to be radiographed is placed in a collimated beam of thermal neutrons. The neutrons are attenuated by elements in the object with high thermal neutron attenuation coefficients as the beam passes through. The remaining neutrons are then collected at the imaging plane. The result is a negative image of the object, with the light areas indicating the greatest neutron attenuation by the object, and the dark areas indicating the least neutron attenuation. The image may be created either through exposing high resolution photographic film (14" x 17") by means of a gadolinium converter screen, or through using a real time Thomson tube video camera.