Abstract International research into the health of people with childhood social care (CSC) experiences has found evidence of worse mental health and emotional-behavioural wellbeing, higher rates of substance use, neurodevelopmental conditions, and avoidable mortality. Lower vaccination rates and worse dental health among those in care has also been reported in few countries. However, research results have been more mixed with regard to some physical health conditions, with higher prevalence of asthma and respiratory ill health among foster children reported in the US but no obvious differences found in the UK. Are there countries where these inequalities are less pronounced, and can we draw such conclusions based on available evidence? When making international comparisons or aiming to give policy advice, we also need to consider the quality of our evidence. Has this been based on small sample sizes or without comparison to other children and adjusting for relevant (socioeconomic) confounders? Most of our current knowledge is also cross-sectional and we do not know if some health conditions precede entry to care and may even be risk-factors for entering social care. Recent longitudinal and cross-sectoral data linkage programmes in many nations (Australia, UK, Canada) have a potential to change this and provide a foundation for evidence-based recommendations for policy and practice.