This book constitutes the refereed proceedings of the 5th International Symposium on Formal Techniques in Real-Time and Fault-Tolerant Systems, FTRTFT'98, held in Lyngby, Denmark, in September 1998. The 22 revised full papers presented were carefully selected and reviewed for inclusion in the book. Also included are four invited contributions and five tool demonstrations. The papers address the current aspects of the hot topic of embedded systems, in particular temporal logic, requirements engineering, analysis techniques, verification, model checking, and applications.