Objectives: This study aims to project attrition from the Australian health and medical research workforce for those aged > 40 years in 2009, through to 2019, and to draw conclusions about the future of this workforce and the international implications of ageing workforce populations. Methods: The study uses recently collected unpublished demographic data on the 2009 health and medical research workforce drawn from an Australian Society for Medical Research survey of health and medical research organisations. Results: About 6250 members of the health and medical research workforce aged > 40 years in 2009 are expected to leave the workforce during 2009-2019; the bulk of these will be aged 50-69 years. It is estimated that 35% of women and 49% of men aged 40-49 years in 2009 will retire by the age of 50-59 years, and 85% of women and 70% of men aged 50-59 years in 2009 are also projected to retire over the next 10 years. Of the 6250 members who are expected to leave the workforce by 2019, about 4000 hold a PhD. As a result of population growth, a further 1700 persons with a PhD will be required if Australia is to maintain its current ratio of PhD-qualified persons in the health and medical research workforce working population to 2019, at a cost of about AU$240 million. Conclusions: There is a need to plan for the replacement of the retiring generation of the health and medical research workforce and for the growth required to match that of the working population. If Australia is to fulfil its ambition for a highly educated, optimally skilled and highly trained health and medical research sector, it must heighten its focus on the higher education of young medical researchers. As population ageing is an emerging phenomenon worldwide, all first world nations are likely to face the challenges involved in replacing a rapidly retiring generation of the health and medical research workforce.