This book constitutes the refereed proceedings of the 13th International Colloquium on Structural Information and Communication Complexity, SIROCCO 2006, held in Chester, UK, July 2006. The book presents 24 revised full papers together with three invited talks, on topics in distributed and parallel computing, information dissemination, communication complexity, interconnection networks, high speed networks, wireless and sensor networks, mobile computing, optical computing, autonomous robots, and related areas.