Background: Mortality, health, and well-being across the lifespan are associated with socioeconomic position (typically operationalised as occupational status). There is some evidence that adolescence represents a period of 'relative equalisation' of health inequalities. Our aim was to examine the association between inequalities in household income and health in childhood and adolescence. Methods: Cross-sectional survey using multistage stratified random sample of households in Britain. Information was collected on 10438 children aged 5-15 years. Results: Low levels of equivalised household income was associated with poorer health for 13 out of the 22 indicators examined (odds ratio P < 0.05 for >= 1 income quintile). Multivariate analyses controlling for child characteristics, parental socioeconomic status and household composition indicated that low levels of equivalised household income increased the odds of poor health for 9 out of the 22 indicators examined. There was little evidence of any systematic differences in the extent of health inequalities across age groups (5-10 and 11-15 years). Conclusion: Household income is related to a range of health outcomes for children and adolescents, even when other indicators of socioeconomic status are taken into account. We found little evidence that adolescence represents a period of relative equalisation of health inequalities.