This book constitutes the refereed proceedings of the Third International Conference on Case-Based Reasoning, ICCBR-99, held in Seeon Monastery near Munich, Germany, in July 1999.The 43 revised papers presented were carefully reviewed and selected from a total of 80 submissions. The book presents mature work and innovative ideas on fundamental and applied research in case-based reasoning and various fields of advanced application. The topics addressed cover the whole spectrum of CBR from formal logics and knowledge-based systems to software engineering, workflow management, decision making, etc.