Grandparents are becoming an increasingly important source of childcare. However, caring for grandchildren may have negative health consequences particularly for grandparents with intensive commitments such as those with primary care responsibilities. To date most studies on this issue are based on cross-sectional data and do not take earlier life circumstances into account. Thus, it is not known whether (or to what extent) the relationship between grandparental childcare and health is due to cumulative advantage or disadvantage throughout the lifecourse or to the impact of grandchild care per se. Employing data from waves 1–3 of the Survey of Health, Ageing and Retirement in Europe we investigated the longitudinal relationship between grandparental childcare (i.e. intensive and non-intensive) and health once cumulative histories of advantage or disadvantage are taken into account. We used latent class analysis to categorise respondents according to childhood socio-economic and health conditions drawing on life history information. Experiences in adulthood (e.g. periods of ill health) were also captured. We created a latent continuous physical health variable based on self- and observer-measured indicators. OLS regression was used to explore the association between physical health at wave 2 and grandparental childcare at baseline, controlling for conditions in childhood and adulthood, and for health and socio-economic characteristics. We found a positive longitudinal association between grandchild care and health even after earlier life health and socio-economic conditions were taken into account. However, this significant association was found only for grandmothers, and not grandfathers. Our results suggesting the health benefits of grandchild care are important given the widespread provision of grandparental childcare in Europe. However, further research on underlying mechanisms and causal pathways between grandchild care and grandparent health, as well as on gender differences in the pattern of association, is needed. •Early and later life health and socio-economic circumstances are associated with grandparenting.•Grandmothers providing childcare experience better physical health.•Grandparenting effect on health remains significant even in a life-course approach.