School-based programs are recommended by the World Health Organization (WHO) to promote mental health for young people. However the effectiveness of such programs varies, and there are multi-level challenges to embedding mental health education in schools. Further, critical scholarship has focused on the ways in which such programs can contribute to neoliberal goals, rather than empowering students meaningfully. Our research used focus group interviews to capture the perspectives and experiences of teachers and children participating in a school-based program in Hong Kong. We applied Bernstein’s theory of pedagogic practices to analyze the interview data, in particular the concepts of boundaries and framing. We identified rigid boundaries between classrooms, the wider school, and home. Boundaries between academic and wider learning, and between school leaders and teachers, hindered cultural change towards mental wellbeing in schools. The program in this study reduced boundaries between students, and between students and teachers. This enhanced students’ communication, and bonding with peers and teachers. School culture about mental health education was found to have weak framing, with students having more influence on the learning process in this program than they currently do in other subjects. We argue that understanding boundaries and framing underpins development of better pedagogic practices in mental health education. When rooted in careful analysis of power relationships with school cultures, mental health promotion is not necessarily aligned with dominant values in society that privilege academic success over wellbeing. School-based programs can provide co-learning spaces for teachers and students, that encourage learning about mental health. © 2023 Informa UK Limited.