The management of chronic patients is a complex process, which requires the cooperation of all primary care professionals and their interaction with specialists, laboratories and personnel of different organizations. In this paper we show how a Careflow Management System (CfMS) may represent an essential component of an innovative Health Information System (HIS) able to handle the information and communication needs underlying chronic diseases management. On the basis of a general architecture designed for chronic diseases, we describe a CfMS implementation in the area of Diabetes management; such a system embeds EPR and telemedicine functionalities as end-users applications as well as a module for inter-organizational communication based on contracts and on XML messages.