This book presents 12 revised refereed papers selected as the best from 32 submissions for the First International Workshop on Tools and Algorithms for the Construction and Analysis of Systems, TACAS '95, held in Aarhus, Denmark, in May 1995.The workshop brought together 46 researchers interested in the development and application of tools and algorithms for specification, verification, analysis, and construction of distributed systems. The papers included in the book are devoted to refinement-based and compositional verification, construction techniques, analysis and verification via theorem proving, process algebras, temporal and modal logics, techniques for real-time, hybrid and probabilistic systems, and value-passing systems.