Positive Behaviour Intervention and Supports (PBIS) is a framework for defining, teaching, and supporting appropriate social and academic behaviour in the school setting. This framework is widely implemented across the world, including Australia. Studies evaluating the effectiveness of PBIS confirm a relationship between implementation fidelity and student outcomes. Abundant literature highlights the significance of parent involvement (PI) on children's social and academic outcomes. However, a consistently and surprisingly under researched component of PBIS is the involvement and influence of parents/caregivers. This article presents the findings of an original qualitative study using stakeholder interviews and artefact analysis to assess parent/caregiver involvement during PBIS implementation in two primary schools in South-West Sydney, Australia. These findings indicate that parent/caregiver involvement in PBIS implementation was interpreted differently by teachers and parents/caregivers and that there is potential for the development of improved methods to engage parents/caregivers more effectively in schools. Reframing parent/caregiver involvement in PBIS to address cultural sensitivities can progressively influence and stabilise this involvement to positively affect the sustainability, effectiveness and fidelity of PBIS. Limitations of the study together with recommendations for future practice are discussed.