The more recent discussion in Ireland around post-primary teachers being responsible for assessing their own students' work continues.The new junior cycle reform (covering the first three years of post-primary education) is concerned with making fundamental changes in approaches to learning, teaching, curriculum and assessment, with school-based assessment as an important element of the reform. This paper sets out to map assessment policy in a changing and contested assessment environment in the Republic of Ireland. The paper tells the story of assessment in junior cycle from the first progress report in 1999 on a review of the curriculum that had been introduced for students in the junior cycle of post-primary schools in 1989 to the 2015 Framework for Junior Cycle. We document the intention to move away from assessment as solely a means of making summative judgements towards assessment as a support of learning and teaching.