The Child Mental Health Service (CMHS) is an Australian primary care program introduced in July 2010 to provide mental healthcare to children who have, or are at risk of, developing psychological disorders. The Australian Government provided supports (e.g., training for mental health professionals), resources (e.g., funding for positions devoted to fostering inter-agency linkages or partnerships) and various flexibilities in service delivery. This study aimed to explore the processes used in the implementation of the CMHS in order to achieve its objectives of delivering a high quality standard of service, and forging linkages and support networks with other relevant health and non-health agencies. Structured interviews were conducted with 20 program administrators, six referring professionals and eight mental health professionals. Interviews were recorded, transcribed and analysed for themes using NVivo. The CMHS appears to have made good progress towards achieving its objectives by implementing processes that facilitated the delivery of a high quality service (e.g., engaging appropriately qualified, and encouraging additional training and clinical support for, mental health professionals; employing quality assurance mechanisms and clinical governance arrangements) and establishment of inter-agency linkages (e.g., devoting a professional role—Coordination and Liaison—to this purpose). Provider perspectives suggest that the CMHS has had a positive impact on children and their families. Comparable countries implementing primary mental health programs for children may benefit from considering similar additional supports (e.g., training for mental health professionals), resources (e.g., funding positions devoted to fostering service inter-agency linkages) and service delivery flexibilities as those available in the CMHS.