This book constitutes the refereed proceedings of the 6th International Symposium on Static Analysis, SAS'99, held in Venice, Italy in September 1999. The 18 revised full papers presented together with five invited contributions, were carefully reviewed and selected from 42 submissions. The book presents the state of the art in Static Analysis. The papers are organized in sections on synchronization in Java programs, synchronous languages, abstract domains, concurrency, static single assignment, and foundations.