Nursing in New Zealand, has been a recognised profession for one hundred years. Throughout this time the profession has made a significant contribution to the health of communities, nationally and internationally. Despite the obvious effort and achievement, the evidence of this contribution is not well known, is documented in a few literature sources only although it is talked about widely as part of 'myth and legend'. Nurses, now as never before, are challenged to show how they 'add value' and to explain why nursing expertise is essential to safe service delivery. Finding a way to communicate this contribution has been identified as one of the most important issues facing the profession. This thesis explores the concept of contribution and presents a model, the 'Contribution Model', to show how nursing can articulate the action and achievements that show how nursing professionals have and will continue to contribute to health gain in New Zealand. Through the application of the 'Contribution Model' and framework presented in this thesis, nursing is shown to have made a contribution to health gain by using the broad range of knowledge, skills and experiences in a wide range of settings, to provide care wherever and whenever required. Case studies and scenarios from history, observation and prediction are used to show how the actions and achievements of nursing meet the expectations of individuals, the community and society: past, present and future