This volume contains the workshop proceedings of DEON 2004, the Seventh International Workshop on Deontic Logic in Computer Science. The DEON workshop series aims at bringing together researchers interested in topics - lated to the use of deontic logic in computer science. It traditionally promotes research in the relationship between normative concepts and computer science, arti?cial intelligence, organisation theory, and law. In addition to these topics, DEON 2004 placed special emphasis on the relationship between deontic logic and multi-agent systems. The workshop was held in Madeira, Portugal, on 26โ28 May 2004. This v- ume includes all 15 papers presented at the workshop, as well as two abstracts from the two outstanding invited speakers we were privileged to host: Prof Mark Brown (Syracuse University, USA), and Prof Mike Wooldridge (University of Liverpool, UK). The reader will ?nd that the topics covered span from t- oretical investigations on deontic concepts and their formalisation in logic, to the use of deontic formalisms to verify and reason about multi-agent systems applications. We believe this makes it a well-balanced and interesting volume. We wish to thank all those who contributed to this workshop, and especially the authors of the submitted papers and the referees. They were all forced to work on a very tight timescale to make this volume a reality.