This book constitutes the refereed proceedings of the 7th International Symposium, Latin American Theoretical Informatics, LATIN 2006, held in Valdivia, Chile in March 2006.

The 66 revised full papers presented together with 7 invited papers were carefully reviewed and selected from 224 submissions. The papers presented are devoted to a broad range of topics in theoretical computer science with a certain focus on algorithmics and computations related to discrete mathematics as well as on cryptography, data compression and Web applications.