Partnerships among service providers are an important aspect of human service delivery, including in the early childhood and family service sector. There is extensive international literature on factors contributing to partnerships – also termed service coordination, collaboration or integration – but little evidence of partnership outcomes exists where partnerships are a funded and mandatory component of large-scale programmes. This paper reports findings from an evaluation of the Australian Government’s Communities for Children (CfC) programme. Under CfC, partnerships were mandated and funded, and the evaluation findings show that the programme resulted in an increased number of agencies working together to support families with young children (0–5 years) and that working relationships between agencies improved. The effectiveness of these partnerships depended on funding for partnership activities and on organisational and practical factors.