The Symposium on Effects of Radiation on Substructure and Mechanical Properties of Metals and Alloys was presented at Los Angeles, Calif., 26-28 June 1972 in conjunction with the Seventy-fifth Annual Meeting of the American Society for Testing and Materials. The symposium was sponsored by ASTM Committee E10 on Radioisotopes and Radiation Effects. John Moteff, Materials Science and Metallurgical Engineering Department, University of Cincinnati, served as chairman of the symposium committee, which consisted of C. J. Baroch, A. L. Bement, E. Landerman, F. R. Shober, and K. M. Zwilsky. The six sessions were presided over by: L. R. Steele, H. Bohm, J. R. Weir, T.T. Claudson, I. P. Bell and K.M. Zwilsky, and S.D. Harkness and C. Y. Li.