The retention of "at risk" students in secondary schools is a major challenge to inclusive education policy. Students with non-compliant behaviour at this level are typically dealt with by authoritarian and punitive disciplinary systems that frequently lead to exclusion from school. This paper reports on the successful establishment of a positive behaviour support system in a secondary school. School-wide systemic change was developed to support the inclusion of students at risk of failure and suspension for non-compliant behaviour. The programme led to the retention of all students in the identified cohort and improved academic performance for all the students. Classroom instructional patterns incorporating evidence-based strategies to engage students, goal setting and self management skills were introduced. Collaborative problem solving with students and teachers ensured intervention integrity. The outcome of the programme and extension at a systemic level for the whole school is briefly discussed.