X-ray scattering and diffraction techniques were used to evaluate degradation of oak wood by gamma radiation. Samples were exposed to 650, 950, and 1,900 Megarads radiation. Chemical analyses (lignin, extractives, and holocellulose content) and density measurements were made on the irradiated samples. Results indicate that cellulose crystallinity was reduced with increasing irradiation and is destroyed at a dosage of 1,900 Megarads. Small-angle X-ray scattering studies were clarified by the use of these additional analytical methods