The Symposium on Damage Tolerance in Aircraft Structures was conducted in two sessions at the Seventy-third Annual Meeting of the American Society for Testing and Materials, held in Toronto, Ontario, Canada, 21-26 June 1970. The symposium was sponsored by ASTM Committee E09 on Fatigue. M. S. Rosenfeld, of the Naval Air Development Center, served as symposium chairman, with P. C. Paris, Del Research Corp., Hellertown, Pa., and R. J. Hebert, Canadair, Ltd., Montreal, Ontario, presiding as chairmen of the first and second sessions, respectively.