OBJECTIVE This study aims to describe implementation of simulator-based medical team training and the effect of this programme on inter-professional working in an intensive care unit (ICU). METHODS Over a period of two years, 90 percent (n = 152) of the staff of the general ICU at Karolinska University Hospital, Huddinge, Sweden, received inter-professional team training in a fully equipped patient room in their own workplace. A case study method was used to describe and explain the planning, formation, and results of the training programme. RESULTS In interviews, the participants reported that the training had increased their awareness of the importance of effective communication for patient safety. The intervention had even had an indirect impact by creating a need to talk, not only about how to communicate efficaciously, but also concerning difficult care situations in general. This, in turn, had led to regular reflection meetings for nurses held three times a week. Examples of better communication in acute situations were also reported. However, the findings indicate that the observed improvements will not last, unless organisational features such as staffing rotas and scheduling of rounds and meetings can be changed to enable use of the learned behaviours in everyday work. Other threats to sustainability include shortage of staff, overtime for staff, demands for hospital beds, budget cuts, and poor staff communication due to separate meetings for nurses and physicians. CONCLUSIONS The present results broaden our understanding of how to create and sustain an organizational system that supports medical team training.