This book constitutes the refereed proceedings of the 5th International Workshop on Cooperative Information Agents, CIA 2001, held in Modena, Italy, in September 2001. The 12 revised full papers presented together with 3 full papers and 2 abstracts reflecting invited contributions were carefully reviewed and selected for inclusion in the book. The papers are organized in topical sections on personal assistance: interaction and avatars, information search and recommendation, data warehousing and data mining, collaboration and coordination, and information agents for mobile and wireless environments.