Our study extends the understanding of how three distinct environments including home, childcare, and neighbourhood may influence young children’s problematic behaviours among a sample of predominantly unmarried mothers residing in urban communities in the United States. With a sample of 791 mothers we examined whether neighbourhood disadvantage and poverty were associated with maternal self-efficacy and parenting stress, the level of cooperativeness between parents and early childcare educators, and the quality of childcare, and whether these factors are in turn associated with toddler behaviour problems. Parent-educator cooperation and the quality of childcare were modest, yet significant protective factors for toddlers’ problematic behaviours while maternal parenting stress was the strongest risk factor. Mothers’ self-efficacy was indirectly associated with problematic behaviours. Neighbourhood poverty was also identified as a risk factor. Our study highlights the importance of cooperative parent-educator relationships for families with lower incomes and the need to account for the neighbourhood context. (author abstract)