This volume contains the proceedings of the 11th International Symposium on Superalloys held September 14-18, 2008, in Champion, Pennsylvania. The symposium covered all aspects of the development, production, behavior and integration of superalloys, and related high temperature materials, into gas turbines for aircraft, power generation and other applications. Symposium topics included cast, wrought and powder superalloys and associated coating systems. Behavioral studies in these areas were also discussed: solidification processing environmental properties mechanical behavior alloy development life prediction methodologies modeling and simulation performance of materials in service environments high temperature coatings joining and repair techniques Emphasis is placed on the perspective of the customer, e.g., the airlines, military, and power generation utilities. Current trends in customer requirements and the latest response of the superalloys community to customer challenges are highlighted in the volume.