Annotation. This book constitutes the proceedings of the 17th International Symposium on String Processing and Information Retrieval, SPIRE 2010, held in Los Cabos, Mexico, in October 2010. The 26 long and 13 short papers presented were carefully reviewed and selected from 109 submissions. The volume also contains 2 invited talks. The papers are structured in topical sections on crowdsourcing and recommendation; indexes and compressed indexes; theory; string algorithms; compressions; querying and search user experience; document analysis and comparison; compressed indexes; and string matching.