This book constitutes the refereed proceedings of the 4th International Conference on Computational Linguistics and Intelligent Text Processing, CICLing 2003, held in Mexico City, Mexico in February 2003. The 67 revised papers presented together with 4 keynote papers were carefully reviewed and selected from 92 submissions. The papers are organized in topical sections on computational linguistics formalisms; semantics and discourse; syntax and POS tagging; parsing techniques; morphology; word sense disambiguation; dictionary, lexicon, and ontology; corpus and language statistics; machine translation and bilingual corpora; text generation; natural language interfaces; speech processing; information retrieval and information extraction; text categorization and clustering; summarization; and spell-checking.