Aim. This paper is a report of a longitudinal study to develop an understanding of the phenomena of Clinical Development Unit (Nursing) leadership by exploring the experiences of the nurse leaders of nine Australian units as they attempted to develop their existing wards or units into recognized centres of nursing excellence. Background. The concept of Clinical Development Unit (Nursing) in Australia originated in the British Nursing Development Unit movement, which has been widely credited with introducing innovative approaches to developing nurses and nursing. A network of nine Clinical Development Units (Nursing) was set up in a suburban area health service in Australia. The aim was to develop existing wards or units into centres of excellence by disseminating a new vision for Australian nurses that was based on the pioneering work of the British Nursing Development Unit movement. Methodology. Principles of Heideggerian hermeneutic phenomenology provided a framework for the study. Nine Clinical Development Unit (Nursing) leaders participated in qualitative interviews from 1998 to 2002. These interviews were transcribed into text and thematically analysed. Findings. Despite attempts to implement a variety of measures to nurture these Clinical Development Units (Nursing) until they had become well established, the new Clinical Development Unit (Nursing) leaders were unable to maintain the Clinical Development Unit (Nursing) vision with which they had been entrusted. This paper discusses their reactions to the problems they faced and the new understandings they developed of their Clinical Development Unit (Nursing) role over time. Conclusion. The findings illuminate the difficulties involved in maintaining the commitment of all levels of staff and management when attempting to introduce new nursing projects.