Adolescence is a time of great physical, emotional and social development complicated by a key organisational change in schooling. This study investigated what young people in primary school reported being worried about with their impending move to secondary school, and how their expectations of the transition experience predicted their actual experience. A sample of 2078 students aged 12–13 years enrolled to attend 20 Perth metropolitan Catholic secondary schools was invited to complete two surveys six months apart, the first at the end of Grade 7, followed by Term 1 of Grade 8. The data indicate one half of all Grade 7 students anticipate a positive transition experience, yet almost 70% of students in Grade 8 report the transition was a positive experience for them, with boys reporting a more positive transition experience overall. Moreover, students who expected a positive transition were more than three times more likely to report an actual positive transition experience. These findings and information about what boys and girls are most looking forward to or worried about at secondary school are presented and implications for future interventions explored.