The theory behind the PDU model is outlined and the key principles underpinning it are identified. The PDU approach is clearly differentiated from the Nursing Development Unit model. Implementation of key principles is explored in depth, with reference to specific work carried out in the PDU. Issues of evaluation, potential future developments and applications of the PDU model are also discussed. The book is for nurses and other practitioners working in PDUs and NDUs, and for health professionals in any setting with an interest in clinical innovation, practice development, research and leadership of multi-professional teams.