The aim of this study was to identify intensive care nurses' perceptions of protocol-directed weaning, by means of focus group interviews and qualitative content analysis. The results showed that the nurses perceived the protocol as useful. When prescribed, it represented interprofessional agreement that allowed them to act in the absence of a physician. It focused on weaning, saved time, was easy to use and led to a feeling of safety and continuity in the weaning process. Barriers to its use were related to lack of instructions from physicians. Nurses reported three ways of handling the situation in the absence of a weaning plan: taking action, waiting, and giving weaning low priority, which could lead to undesired variations. Nurses in this study reported that they would like an interdisciplinary approach to weaning and expressed the need for a shared "language" or knowledge base in order to improve communication. It is important that different disciplines meet to share each other's knowledge. Contact is vital in order to learn about and respect different types of professional knowledge.