This book constitutes the refereed proceedings of the 6th International Conference on Flexible Query Answering Systems, FQAS 2004, held in Lyon, France in June 2004.

The 35 revised full papers presented together with 3 invited papers were carefully reviewed and selected from more than 100 submissions.

The papers are organized in topical sections on knowledge representation; knowledge discovery and data mining; domain modeling, ontologies, and human interaction; computational linguistics and natural language processing; Web services, databases; information retrieval; and logic and artificial intelligence.