The CGIAR Research Program on Aquatic Agricultural Systems (AAS) is increasingly using the language of transformation to describe its aims and approach to achieving lasting impact at scale. Clarity on what AAS means by 'transformation' is important to ensure that use of the term is intentional and meaningful. AAS wants to avoid the risk befalling a number of terms used in the development field-i.e., empowerment and participation-which are applied by such a wide range of actors with divergent intent and ideology that the terms lose meaning. The aim of this brief is to articulate the program's understanding of 'transformation' through review of different definitions of the term in various disciplines and comparison with a definition of 'development'. It then explores different areas in which AAS can foster transformation based on emergent learning among program leaders and articulation of the program's scaling pathways. It ends with a section on how the AAS program intends to foster transformative change through a participatory action research approach.