Home visiting programmes are increasingly being implemented across the globe to help vulnerable families with young children, however longer-term experimental evidence on their health impacts on both parents and children is scarce. In this paper we study the medium-term health impacts of a randomized control trial to evaluate the Nurse Family Partnership (NFP), one of the oldest home visitation programs, at scale in the United States and England. Using objective measures of health, we find that the intervention led to large and sustained reductions in child obesity and maternal hypertension, which are concentrated in girls and their mothers. We further examine rich survey data on pre- and post-natal investments, parenting and maternal socio-economic status, linked administrative records on welfare receipt, and detailed information on programme implementation, to explore potential mechanisms. Our results provide importance new evidence on the potential role of prenatal and infancy home visiting in preventing or delaying the onset of costly chronic health conditions.