Abstract Objective To review a collaborative Lean methodology involving various health professionals for the improvement of interprofessional work and the coordination of care during patient hospitalization to reduce length of stay. Design/methodology/approach Two similar Lean projects were carried out in the geriatric care unit of two hospitals of the Centre Hospitalier Universitaire de Quebec (CHU de Quebec). The projects focused on interprofessional collaboration through Lean activities for improving the geriatric patient trajectory and discharge processes. The mean length of stay in the geriatric care unit was measured before and after the project. Secondary outcomes were the length of stay in the emergency room (ER) and the number of medical consultations realized by a geriatric physician in the ER. Findings Projects led to a new shared vision of interprofessional approach in both geriatric care units. The mean length of stay for the first geriatric care unit was reduced by 3 days and by 7 days for the second unit. Optimization in ER flow also been observed for both projects. Originality/value These interprofessional Lean projects described how a group of various professionals could change their vision from a shared decision making of patient discharge to a collaborative workflow of cares by designing together the process and not focussing on individuals. This collaborative workflow is possible by implementing an interprofessional focus on communication, role clarification and the autonomy of all healthcare professional as soon as the patient is admitted to the ER and during the whole hospitalization period.