This book constitutes the refereed proceedings of the 5th International Conference on Formal Methods in Computer-Aided Design, FMCAD 2004, held in Austin, Texas, USA in November 2004. The 29 revised full papers presented together with the abstract of an invited talk were carefully reviewed and selected from 69 submissions. The papers address all current issues on tools, methods, algorithms, and foundational theory for the application of formalized reasoning to all aspects of computer-aided systems design, including specification, verification, synthesis, and testing.