Objective: This study examines the uptake by children aged predominantly 0-11 years of an Australian primary mental health service - the Access to Allied Psychological Services programme - which began in 2001. In particular, it considers access to, and use of, the child component of Access to Allied Psychological Services, the Child Mental Health Service, introduced in 2010. Method: Using routinely collected programme data from a national minimum dataset and regional population data, we conducted descriptive and regression analysis to examine programme uptake, predictors of service reach and consumer- and treatment-based characteristics of service. Results: Between 2003 and 2013, 18,631 referrals for children were made and 75,178 sessions were scheduled via Access to Allied Psychological Services, over 50% of which were via the Child Mental Health Service in its first 3 years of operation. The rate of referrals for children to the Child Mental Health Service was associated with the rate of Access to Allied Psychological Services referrals for consumers aged 12+ years. Conclusions: The Child Mental Health Service has increased services provided within the Access to Allied Psychological Services programme for children with emotional and behavioural issues and their families, and is potentially filling a service gap in the area of prevention and early intervention for children who have significant levels of need but are unable to access other mental health services. Our findings are policy-relevant for other developed countries with a similar primary mental health care system that are considering means of improving service access by children.