It is our pleasure to present in this volume the proceedings of the 7th Inter- tional Workshopon InformationHiding (IH 2005),held in Barcelona,Catalonia, Spain, during June 6-8, 2005. The workshop was organized by the Department of Computer Science and Multimedia, Universitat Oberta de Catalunya (UOC). Continuing the tradition of previous workshops, we sought a balanced p- gram, containing talks on various aspects of data hiding, anonymous commu- cation, steganalysis, and watermarking.Although the protection of digital int- lectual property has up to now motivated most of our research, there are many other upcoming ?elds of application. We were delighted to see that this year's workshop presented numerous new and unconventional approaches to infor- tion hiding. The selection of the program was a very challenging task. In total, we - ceived 90 submissions from 21 countries. At this point we want to thank all authors who submitted their latest work to IH 2005-and thus assured that the Information Hiding Workshop continues to be the top forum of our community.