This volume contains the proceedings of the 7th International Seminar on - lational Methods in Computer Science (RelMiCS 7) and the 2nd International Workshop onApplications ofKleeneAlgebra. Thecommonmeetingtookplacein Bad Malente (near Kiel), Germany, from May May 12-17,2003. Its purpose was to bring together researchers from various subdisciplines of Computer Science, Mathematics and related?elds who use the calculi of relations and/or Kleene algebra as methodological and conceptual tools in their work. This meeting is the joint continuation of two di?erent series of meetings. Previous RelMiCS seminars were held in Schloss Dagstuhl (Germany) in J- uary 1994, Parati (Brazil) in July 1995, Hammamet (Tunisia) in January 1997, Warsaw (Poland) in September 1998, Quebec (Canada) in January 2000, and Oisterwijk (The Netherlands) in October 2001. The?rst workshop on appli- tions of Kleene algebra was also held in Schloss Dagstuhl in February 2001. To join these two events in a common meeting was mainly motivated by the s- stantialcommoninterestsandoverlapofthetwocommunities. Wehopethatthis leads to fruitful interactions and opens new and interesting research directions.