This book constitutes the refereed proceedings of the 12th International Conference on Database and Expert Systems Applications, DEXA 2001, held in Munich, Germany in September 2001. The 93 revised full papers presented were carefully reviewed and selected from 175 submissions. The papers are organized in topical sections on advanced databases, information retrieval, digital libraries, user interfaces, multimedia databases, workflow aspects, active databases, spatial databases, distributed databases, web aspects, knowledge management aspects, datawarehouses, hypermedia, indexing, object-oriented databases, database queries, and transaction processing.