The paper is concerned with data, concepts and analyses necessary for understanding the nurse and midwifery workforces at a macro-level, and for developing policies and plans that can best assure the quality and sufficiency of those workforces in the future. The size, composition and age profile of the nurse workforce are set out first. This is followed by an outline of the notions of 'attachment' to and 'separation' from a profession. Data on the population with professional nurse qualifications, whether working in the profession, in another occupation, or not working illustrates the patterns of 'attachment' and 'separation' over the working age range. Historical developments since the 1960s are then considered, including the workforce size and age profile, the nurse labour market, pre-registration course completions, and movement in and out of Australian of nursing professionals. The nature and impact of the 'oversupply' of nurses in the early- to mid-1990s is discussed. Six matters are outlined that need to be taken into account when estimating future requirements. A discussion of the potential for quantitative impact on the overall nurse labour market from work redesign and role extension concludes that there is no easy solution for macro-level nurse workforce shortages, and that some otherwise very positive initiatives may exacerbate shortages. It is clear that further increases in pre-registration (and pre-enrolment) intakes and completions will be necessary, as least for a further 8-12 years. Some of the barriers to such increases are noted and suggestions for the future made.