This paper describes the development and use of the Creative Learning Assessment (CLA) as a means of evidencing, supporting and promoting children's creative learning in arts-based contexts. The research team at the Centre for Literacy in Primary Education (CLPE) worked with a group of teachers in inner-city Lambeth primary schools to develop an assessment system to record the impact of a creative curriculum on children's achievement and to enable schools to justify a broad-based provision. The Assessing Learning and Communication in Creative Learning Contexts project, funded by CfBT Education Trust (CfBT), aimed to offer teachers a view of creative learning development and a framework for teacher assessment. It set out to provide a close focus on the learner and a valuable source of information for curriculum planning. This article discusses the effect of working with the CLA on children's learning and on teachers' practice through a case study of one project school, and the implications for schools and classrooms from the perspectives of the researcher and the teacher.