This book constitutes the refereed proceedings of the Second International Conference on Fundamental Approaches to Software Engineering, FASE'99, held in Amsterdam, The Netherlands, in March 1999 as part of ETAPS'99. The 13 revised full papers presented were carefully reviewed and selected for inclusion in the book. Also included are two invited papers and two demo presentations. Among the topics addressed are formal methods, real-time specifications, process calculi, reactive concurrent systems, term rewriting, dynamic systems, UML modeling, systems verification, program development, and theorem proving.