Public health doctors are required to audit their work, a principle endorsed by the Faculty of Public Health Medicine. Although general concepts of audit in clinical medicine are likely to apply to public health medicine, the practical problems are likely to be different. Public health medicine, therefore, needs to experiment with approaches to audit until general principles are established. The implementation of public health medicine audit in the Northern Region is reviewed here, highlighting the establishment of structures (e.g. a public health medicine audit promotion group and audit link-persons), processes (e.g. study days, exchange of information) and outcomes (e.g. audits undertaken and standards devised). The foundations for audit of public health medicine have been built upon wide debate and consultation, locally written documents detailing the arguments and making practical suggestions for change, ownership of policy-making decisions by a regional forum of public health doctors, day-to-day responsibility resting in an audit group, a heavy emphasis on communication including the gauging of opinions, attitudes and behaviour by survey, a perception that public health medicine has the same rights and obligations towards audit as other medical specialties, and the view that audit in our specialty will require time and patience to implement. The challenge remains of ensuring the implementation of cost-effective audit in the routine practice of public health medicine.