The Proceedings of the 3rd Brazilian Symposium on Information Systems (SBSI 2006) bring the papers selected and presented in the Curitiba – PR on November 8-10, 2006. In this issue, the proceedings include 39 full papers. These papers were selected through a blind review, from a total of 171 full papers, which implied an acceptance rate of 22,8%. The event's program committee was coordinated by Alexandre Reis Graeml (UnicenP) and Alexandre Cidral (Univille), who organized this volume. The articles in this volume were submitted on October 8, 2006, accepted for publication on November 22, 2006, with the final version submitted on December 7, 2006.