Nursing development units (NDUs) are centres where groups of nurses, midwives, public health nurses and health visitors use a comprehensive planned strategy to develop themselves and their practice. Some of the early defining work on NDUs is considered and a brief history is outlined in this article. The strategic approach taken by the Eastern Health Shared Services in Dublin has led to the development of many NDUs in the Dublin area over a five-year period. The NDUs are based on a strategic, supportive approach. Six now exist in the state-funded health service system, but the project has also been widened to include the private and voluntary sectors and this has stimulated several other units to emerge. Focus group work with NDU leaders and facilitators has led to a gradual redefining of the principles of NDUs and the emergence of an accreditation system run by the board. The authors summarise these findings.