Previous studies have shown that self-reported health indicators are predictive of subsequent mortality, but that this association varies between populations and population sub-groups. For example, self-reported health is less predictive of mortality at older ages, has a stronger association with mortality for men than for women and is more predictive of mortality for those of lower than those of higher socio-economic status, particularly among middle aged working adults. This article explores this association using individual level, rather than ecological, data to see whether there are differences between the constituent countries of the UK in the relationship between self-reported health and subsequent mortality, and to investigate socio-economic inequalities in mortality more generally. Data are used from the three Census based longitudinal studies now available for England and Wales, Scotland and Northern Ireland.List of tables, 13.