In this article, an action-research project has been outlined, aimed at exploring ways for developing an assessment tool, underpinned by phenomenology, which would enhance a person-centered approach to the participation of patients in nursing assessment and care planning in rehabilitation. Participants were nurses in physical rehabilitation and a consultant. Data were collected by interviews and observation of the documentation on the tool. The tool, Hermes, was adopted in practice. Through its use, important person-centered assessment practices were enhanced and several aspects of its phenomenological grounding were supported. Hermes has potential for facilitating the transfusion of phenomenology into nursing practice.