This book constitutes the refereed proceedings of the 10th International Conference on Computational Linguistics and Intelligent Text Processing, CICLing 2009, held in Mexico City, Mexico in March 2009. The 44 revised full papers presented together with 4 invited papers were carefully reviewed and selected from numerous submissions. The papers cover all current issues in computational linguistics research and present intelligent text processing applications. th CICLing 2009 markedthe 10 anniversary of the Annual Conference on Intel- gent Text Processing and Computational Linguistics. The CICLing conferences provide a wide-scope forum for the discussion of the art and craft of natural language processing research as well as the best practices in its applications. This volume contains ?ve invited papers and the regular papers accepted for oral presentation at the conference. The papers accepted for poster presentation were published in a special issue of another journal (see the website for more information). Since 2001, the proceedings of CICLing conferences have been published in Springer¿s Lecture Notes in Computer Science series, as volumes 2004, 2276, 2588, 2945, 3406, 3878, 4394, and 4919. This volume has been structured into 12 sections: ¿ Trends and Opportunities ¿ Linguistic Knowledge Representation Formalisms ¿ Corpus Analysis and Lexical Resources ¿ Extraction of Lexical Knowledge ¿ Morphology and Parsing ¿ Semantics ¿ Word Sense Disambiguation ¿ Machine Translation and Multilinguism ¿ Information Extraction and Text Mining ¿ Information Retrieval and Text Comparison ¿ Text Summarization ¿ Applications to the Humanities A total of 167 papers by 392 authors from 40 countries were submitted for evaluation by the International Program Committee, see Tables 1 and 2. This volume contains revised versions of 44 papers, by 120 authors, selected for oral presentation; the acceptance rate was 26. 3%.