This book constitutes the refereed proceedings of the 8th Congress of the Italian Association for Artificial Intelligence, AI*IA 2003, held in Pisa, Italy in September 2003.The 44 revised full papers presented were carefully reviewed and selected from 91 submissions. The papers are organized in topical sections on knowledge representation and reasoning, soft computing, machine learning, data mining, intelligent agents, planning, robotics, natural language processing, and applications in various fields.