This volume presents the 36 full refereed papers selected from the presentations at the First European Workshop on Case-Based Reasoning, held at Kaiserslautern, Germany in November 1993.Case-based reasoning (CBR) has recently attracted much interest among AI researchers: it supports knowledge acquisition and problem solving, and it is related to machine learning, analogical reasoning, cognitive modeling, similarity, and information retrieval. EWCBR is now established as the prime European forum for CBR research. This volume reflects the importance of this dynamic area of research through essential contributions to all aspects of CBR research and advanced applications.