The prison population is known to have relatively poor health, with the poor mental health of prisoners a particular concern. A significant proportion of people in the prison system are Aboriginal and Torres Strait Islander peoples. Despite the needs of prisoners, and the association between prisoners' health and the health of the wider community, there is remarkably little national information available on prisoners. Most health information is either collected through ad hoc surveys or is paper-based and remains in medical records. This report highlights the need for reliable national information about the health of prisoners at the point of reception, during custody, and at release and post-release. It contains a national audit of current health information collected by each jurisdiction, and lays the foundation for the development of national prisoner health indicators.