The papers in this volume were presented at SWAT 2000, the Seventh Scandi- vian Workshop on Algorithm Theory. The workshop, which is really a conference, has been held biennially since 1988, rotating between the ve Nordic countries (Sweden, Norway, Finland, Denmark, and Iceland). It also has a loose assoc- tion with the WADS (Workshop on Algorithms and Data Structures) conference that is held in odd numbered years. SWAT is intended as a forum for researchers in the area of design and analysis of algorithms. The SWAT conferences are co- dinated by the SWAT steering committee, which consists of B. Aspvall (Bergen), S. Carlsson (Lule a), H. Hafsteinsson (U. Iceland), R. Karlsson (Lund), A. Lingas (Lund), E. Schmidt (Aarhus), and E. Ukkonen (Helsinki). The call for papers sought contributions in all areas of algorithms and data structures, including computational geometry, parallel and distributed comp- ing, graph theory, and computational biology. A total of 105 papers were s- mitted, out of which the program committee selected 43 for presentation. In addition, invited lectures were presented by Uriel Feige (Weizmann), Mikkel Thorup (AT&T Labs-Research), and Esko Ukkonen (Helsinki). SWAT 2000 was held in Bergen, July 5-7, 2000, and was locally organized by a committee consisting of Pinar Heggernes, Petter Kristiansen, Fredrik Manne, and Jan Arne Telle (chair), all from the department of informatics, University of Bergen.