This book constitutes the refereed proceedings of the 13th Portuguese Conference on Artificial Intelligence, EPIA 2007, held in Guimarães, Portugal, in December 2007 as eleven integrated workshops.The 58 revised full papers presented were carefully reviewed and selected from a total of 210 submissions. In accordance with the eleven constituting workshops, the papers are organized in topical sections on general artificial intelligence (GAIW 2007), AI applications for sustainable transportation systems (AIASTS 2007), artificial life and evolutionary algorithms (ALEA 2007), ambient intelligence technologies and applications (AMITA 2007), building and applying ontologies for the semantic Web (BAOSW 2007), business intelligence (BI 2007), computational methods in bioinformatics and systems biology (CMBSB 2007), intelligent robotics (IROBOT 2007), multi-agent systems: theory and applications (MASTA 2007), search techniques for constraint satisfaction (STCS 2007), and text mining and applications (TEMA 2007).