Despite great concern about child well-being, and an increasing recognition of the need to monitor how well children are doing, small area measures of child disadvantage are a very recent development in understanding child well-being both within Australia and internationally. This paper describes the further development of Australia’s only small area index of child social exclusion risk. Drawing on the latest conceptual and methodological developments in child indicator research, the authors have identified additional domains and variables to best measure child social exclusion at a small area level. Incorporating new data, the paper then goes on to discuss the use of principal components analysis and equal weighting to transform the individual indicators into domain scores, and then the domain scores into a single composite index.