This book constitutes the refereed proceedings of the 18th International Conference on Advanced Information Systems Engineering, CAiSE 2006, held in Luxembourg, in June 2006. The book presents 33 revised full papers together with 3 keynote talks. The papers are organized in topical sections on security, conceptual modeling, queries, document conceptualization, service composition, workflow, business modeling, configuration and separation, business process modeling, agent orientation, and requirements management.