Based on the Theory of Planned Behavior, we explored the impact of 498 primary school teachers in Hong Kong on the competences of students with special educational needs (SEN). We found that their attitudes, control beliefs, and subjective norms about inclusive education (IE) significantly influenced their IE intentions, and subsequently their behaviors. Intentions and behaviors mediated the effect on the social and academic competencies of SEN students. Our findings, consistent across nine different SEN types, have highlighted the role of fostering positive teacher dispositions and reinforcing IE intentions and behaviors through training and peer support networks, facilitating effective IE implementation. Copyright © 2024 The Authors.