PURPOSE This study aimed to develop the theory of child abuse of children with disabilities in Adapted Physical Education (APE). METHODS A grounded theory study was conducted based on a constructivist approach. Data were collected via in-depth interviews. Participants were 20 instructors selected based on theoretical sampling. The collected data were analyzed in the order of open coding, axial coding, and selective coding. RESULTS First, the direct causal conditions of abuse of children with disabilities in APE were the instructors’ and guardians’ distorted perception towards the disabled children along with the individual vulnerability of children with developmental disabilities. Second, the contextual conditions that form the background of the abuse of children with disabilities in APE included the burden of the instructor due to the unjust demands of the guardian of the child, the growth background of the instructor, and the repressive atmosphere of APE. Third, abuse of children with disabilities can be divided into three types: ‘active abuse’ based on the instructor’s distorted viewpoint of the child with a developmental disability, ‘passive abuse’ due to the unjust demands of the guardian, and ‘passive abuse’ due to the structural problems in the APE field. Fourth, the abuse of children with disabilities in APE, which can be distinguished by different characteristics, affects the instructor’s inner conflict and self-reflection. CONCLUSIONS This study approached the phenomenon of abuse of children with disabilities in Korean adapted physical education as a grounded theory, and the theory generated is expected to contribute to the establishment of strategies necessary to design adapted physical education in keeping with human rights.