BIS 2009 held in Pozna? was the 12th in a series of international conferences on Business Information Systems. The BIS conference series has been recognized by professionals from its very beginning as a forum for the exchange and d- semination of topical research in the development, implementation, application and improvement of computer systems for business processes. The theme of the conference was "Information Systems for Agile Organi- tions." The material collected in this volume covers recent tendencies in making organizations more responsive to external conditions. On the one hand, onto- gies are adopted as a tool for better data and information management. On the other hand, ?exible information systems based on process orientation are being developed. A set of 22 papers illustrating these trends were selected for presentation during the main event. The articles are grouped into the following conference topics: Ontologies in Organizations,Ontologies and Security, Process Modelling, Process Analysis and Mining, Service-Oriented Architecture, Web Search,SocialIssues,andERP. The Program Committee consisted of over 90 members, who carefully ev- uated all the submitted papers. The careful review process assured that each paper underwent thorough evaluation and received many valuable comments. Only the best-quality papers were selected, resulting in an acceptance rate of less than 30%. The regular program was complemented by outstanding keynote speakers. We were honored to host leading experts in business process management and information management: Wil van der Aalst (Eindhoven University of Techn- ogy, The Netherlands) and Asuncion Gomez-Perez (Universidad Politecnica de Madrid, Spain).