The early years are critical and inform the developmental trajectory of children. This is justifiably attracting growing policy attention. Much of this attention is focused on interventions and policies directed at parents, especially mothers. Yet emerging evidence suggests that increasing numbers of children in rapidly urbanizing low- and middle-income countries are now spending much of their day with other formal and informal childcare providers, including largely unregulated paid childcare providers. This paper summarizes the limited literature about the use of such paid childcare in low- and middle-income countries in sub-Saharan Africa, before considering possible reasons behind the lack of research evidence. Finally, key research gaps and their implications for public health practice are explored, with reference to the ongoing British Academy funded Nairobi Early Childcare in Slums research programme in Nairobi, Kenya. We argue that improving childcare may be an under-explored strategy to help some of the world's most disadvantaged children in the most important period of their lives, and that interventions in this largely informal market should be built on a rigorous research base.This article is part of the theme issue ‘Multidisciplinary perspectives on social support and maternal–child health’.