This book constitutes the refereed proceedings of the 24th International Conference on the Foundations of Software Technology and Theoretical Computer Science, FSTTCS 2004, held in Chennai, India, in December 2004. The 35 revised full papers presented together with 5 invited papers were carefully reviewed and selected from 176 submissions. The papers address a broad variety of current issues in software science, programming theory, systems design and analysis, formal methods, mathematical logic, mathematical foundations, discrete mathematics, combinatorial mathematics, complexity theory, automata theory, and theoretical computer science in general