The move from primary school to secondary school has been identified as one of the most significant transitions in the lives of young people. In Australia, most children make the transition from primary to secondary school at around 12-13 years of age. This move involves changes in relationships with peers and teachers, schoolwork, and the school environment. Children often have mixed feelings about the transition and a period of apprehension is normal. These worries are often short lived and usually dissipate within the first term of high school. However, many children struggle with the social, emotional, organisational and academic demands of the transition to high school. The consequences are marked falls in school engagement, attendance, and the academic achievement of children. These, in turn, can lead to adverse outcomes such as higher rates of unemployment and lower income in adult life. In contrast with the investment seen in the early years, the middle years have not seen system-wide approaches within education that prepare children for the transition to secondary school.This study will present data from the Childhood to Adolescence Transition Study (CATS). This is a unique longitudinal study following a cohort of 1239 students annually from 8-9 years of age (grade 3) across Melbourne, Victoria. The sample has been selected to be representative of children across all three education sectors (Government, Independent and Catholic), and includes socially disadvantaged children, children with culturally and linguistically diverse backgrounds and indigenous children. To date four waves of data have been collected; at each wave there is a comprehensive assessment of health, emotional wellbeing, school engagement and academic performance obtained from student self-report, as well as parent and teacher report. NAPLAN data has also been linked at grades 3 and 5. In 2015 (grade 6) key informant interviews were conducted with a representative from each participating school (n=52) on the activities and strategies that they have in place to support students as they transition to secondary school.Data on the adjustment of students in the latter years of primary school and examination of predictors of “readiness for secondary school” will be presented. This study will also examine associations between transition activities conducted by schools and preparedness of students for the transition. The implications for schools and policy-makers will be discussed.