This publication, Mechanical, Thermal and Environmental Testing and Performance of Ceramic Composites and Components, contains papers presented at the Symposium on Environmental, Mechanical, and Thermal Properties and Performance of Continuous Fiber Ceramic Composite (CFCC) Materials and Components held in Seattle, Washington on 18 May 1999. ASTM Committee C28 on Advanced Ceramics sponsored the symposium in cooperation with Committees E08 on Fatigue and Fracture and D30 on Advanced Composites. Michael G. Jenkins, University of Washington, Edgar Lara-Curzio, Oak Ridge National Laboratory, and Stephen T. Gonczy, Gateway Materials Technology, presided as co-chairmen and are co-editors of the resulting publication.