It became apparent in 1998 that there was a significant shortage of nurses and midwives in the Republic of Ireland. Because of the lack of data on the reasons for this, a national study was commissioned to estimate the turnover rate among registered nurses and to identify the underlying reasons for the loss of so many trained staff to the profession. Both quantitative and qualitative methodologies were used. Participants were drawn from 128 health service agencies, and 1,921 questionnaires were completed over a one-year period by nurses and midwives leaving the service. Telephone interviews were also conducted with 140 participants. The results indicate a mean turnover rate of 12%, with considerable variations across services. Reasons for leaving included wanting to pursue other employment in nursing (35%), travel abroad (21%) and a desire to undertake further study (12%). It appeared that a considerable number of nurses would have been retained if retention strategies focusing on promotion of greater autonomy, professional development, managerial support, or improved professional practice environments had been introduced.