This study aimed to explore the constructs related to teachers' competence in immediately intervening in school bullying (CIISB) in order to develop a valid intervention process. In this study, 16 secondary school teachers in Taiwan with experience of dealing with school bullying were interviewed. In total, 26 interview transcripts were analysed. The results highlight two key constructs that are central to CIISB. The first is "structuring prompt management of school bullying." This involves three phases: identifying the incident, stabilising the incident, and clarifying incidents as well as implementing incidental and intentional learning. The second construct is "setting the appropriate atmosphere." This refers to teachers' capacity to build a positive relationship with students by maintaining a calm, serious and fair attitude, and creating a positive atmosphere to implement an immediate intervention. The results suggest that teachers should master the above constructs of CIISB, thereby providing a suitable immediate intervention when school bullying occurs.