Patient management is becoming increasingly complex, particularly because of the growing prevalence ofchronic diseases and ageing populations. The Swiss health care system is fragmented and struggles to coordinate care provided by professionals from multiple disciplines or working for different institutions. Models to improve health care of complex situations are available that particularly advocate a coordinated team approach. This article presents an action-research designed to empower health professionals to manage complex situations in outpatient settings by means of this type of approach. Health professionals - good practice leaders in the medical and nursing fields in the Geneva Canton (Switzerland) - explored complex management situations, as well as facilitating components and obstacles. A team approach is essential to manage all of the patient's issues, to take the patient's priorities into account, and to work on a joint care plan. The legitimate role of each member of this team is highlighted, together with new roles for existing practices: informing and motivating the patient, highlighting and supporting care givers, coordination by nurses. The creation of such teams, and implementation of these roles involve new processes, which require financing of coordination as well as development of new methods of interdisciplinary management, particularly novel information technology tools.