The Symposium on Environmental Effects on Advanced Composite Materials was presented at the Seventy-eighth Annual Meeting of the American Society for Testing and Materials held in Montreal, Canada, 22—27 June 1975. The symposium was sponsored by the Aerospace and Low Temperature Panels of the American Society for Testing and Materials—American Society of Mechanical Engineers—Metal Properties Council Joint Committee on Effect of Temperature on the Properties of Metals. J. L. Christian, General Dynamics, W. E. Witzell, General Dynamics, and B. A. Stein, NASA-Langley Research Center, served as symposium cochairmen.