This study explored the role of relative quantity of green space in urban English neighbourhoods in predicting parent-reported emotional and behavioural problems from early to middle childhood (ages 3, 5, 7) and in buffering the effects of multiple risk factors (neighbourhood disadvantage, family poverty and adverse life events) on child adjustment. We modelled data from 6384 Millennium Cohort Study children using multilevel growth curve modelling. Neighbourhood green space was measured with the percentage of green space within a standard small area. We found that access to garden and use of parks and playgrounds were related to fewer conduct, peer and hyperactivity problems. Neighbourhood green space was generally unrelated to child adjustment, but poor children in urban neighbourhoods with more greenery had fewer emotional problems from age 3 to 5 than their counterparts in less green neighbourhoods. Neighbourhood green space may promote emotional well-being in poor urban children in early childhood.