In this paper the nature of user involvement in a co-design process will be explored. The outlines of a research project aiming at developing support systems for self-care inpatients suffering from chronic heart failure will be presented. The project is planned to perform a co-design effort where users (patients and healthcare professionals) will be given the opportunity to influence the development of support systems. We will discuss a number of possibilities and challenges that lie in the design of this kind of project and also some findings from its early stages. This report presents the experiences of users’ input, which are discussed in the context of previous research on benefits of user contributions in systems development.