In this article, we propose an agent-based approach for managing e-commerce activities. In our approach, an agent is present in each e-commerce site, managing the information stored there. In addition, another agent is associated with each customer, handling his/her profile. The proposed approach is based on the use of a particular conceptual model called the Behaviour-Semantic Distance and Relevance (B-SDR) network, which is capable of uniformly representing and handling information stored in e-commerce sites and customer profiles. The capabilities of the B-SDR network model are exploited to let customer and site agents cooperate in such a way in order to support a customer in identifying, whenever he/she accesses an e-commerce site, those products and services present in the site itself and for better matching his/her interests. The approach has been implemented in a prototype in which its functionalities are discussed here also. © 2004 Wiley Periodicals, Inc.A preliminary version of part of the material presented in this article appears under the title “A multi-agent model for handling e-commerce activities” in the Proceedings of the “International Database Engineering and Applications Symposium (IDEAS 2002),” Edmonton, Alberta, Canada, 2002.