The Australian Medical Assessment Collaboration (AMAC) began in 2010. This article charts the development of the collaboration over its initial years. AMAC was instigated as a way of improving the quality of medical education through the recognition of the need for tools for comparison and evaluation of learning outcomes, acknowledgement of the need for high quality assessment, and to share expertise in these areas. In a climate of increasing regulation and accountability, this collaboration was formed as a means of increasing assessment practices by, with and for medical schools. This article provides an overview of the background issues stimulating the development of AMAC, discussion of the formation of the collaboration and reflection on the lessons learnt through these processes. In a relatively short space of time, AMAC has fostered substantial collaboration among schools; developed an Assessment Framework, items and an online assessment; and provided benchmarking reports to students and schools. The intention here is to provide guidance for others (within the medical education community and those in other disciplines) with similar intentions and aims, by outlining the developmental pathway of the project and the systematic lessons that the collaboration team has learnt in establishing AMAC.