This paper describes four summary measures, or indexes, derived from the 2001 Census of Population and Housing to measure different aspects of socio-economic conditions. These indexes are then applied to both the Department of Health and Community Services (DHCS) administrative health districts and to Urban Centres/Localities in the Northern Territory. The four SEIFA indexes are (ABS 2003): Index of Relative Socio-Economic disadvantage; Index of Relative Socio-Economic Advantage/Disadvantage; Index of Economic Resources; and Index of Education and Occupation. These indexes show where the affluent (as opposed to just high income earning) live; where disadvantaged (as opposed to the unemployed) live; and where the highly skilled and educated (as opposed to the tertiary educated people) live.