Public health activities are aimed at preventing illness and enhancing the present and future wellbeing and quality of life of a nation's population. As such, current outlays by governments on public health activities are investments that aim to minimise future preventable expenditure on illness.This publication is the fourth in a series that reports expenditure on public health activities by governments in Australia. it provides detailed estimates of expenditure for the years 2001-02 to 2003-04, as well as some revised estimates for 1999-00 and 2000-01.The report summarises estimates of expenditure and funding from key health departments and agencies of the Australian Government and each state and territory government by nine public health activity categories.