This volume of the Lecture Notes in Computer Science series provides a c- prehensive, state-of-the-art survey of recent advances in string processing and information retrieval. It includes invited and research papers presented at the 10th International Symposium on String Processing and Information Retrieval, SPIRE 2003, held in Manaus, Brazil. SPIRE 2003 received 54 full submissions from 17 countries, namely: – gentina(2), Australia(2), Brazil(9), Canada(1), Chile (4), Colombia(2), Czech Republic (1), Finland (10), France (1), Japan (2), Korea (5), Malaysia (1), P- tugal (2), Spain (6), Turkey (1), UK (1), USA (4) – the numbers in parentheses indicate the number of submissions from that country. In the nontrivial task of selecting the papers to be published in these proceedings we were fortunate to count on a very international program committee with 43 members, represe- ing all continents but one. These people, in turn, used the help of 40 external referees. During the review processall but a few papers had four reviewsinstead of the usual three, and at the end 21 submissions were accepted to be p- lished as full papers, yielding an acceptance rate of about 38%. An additional set of six short papers was also accepted. The technical program spans over the two well-de?ned scopes of SPIRE (string processing and information retrieval) with a number of papers also focusing on important application domains such as bioinformatics. SPIRE 2003 also features two invited speakers: Krishna Bharat (Google, Inc. ) and Joa o Meidanis (State Univ. of Campinas and Scylla Bioinformatics).