OBJECTIVES. To investigate the level of knowledge about emergency management of dental trauma among Hong Kong primary and secondary school teachers. DESIGN. Questionnaire survey. SETTING. A teachers' union that unites 90% of teachers in Hong Kong. PARTICIPANTS. Randomly selected primary and secondary school teachers. RESULTS. Only 32.8% of respondents correctly stated that a person sustaining dental trauma should go to dentists directly. In all, 73.1% of teachers correctly stated that a dental trauma patient should go for treatment immediately. Only 32.5% knew that a fractured tooth should be put in liquid. Even fewer (23.2%) realised that the displaced tooth should be repositioned back to the original position. Relatively more respondents (74.7%) understood that an avulsed baby tooth should not be put back. Disappointingly, only 16.3% of teachers knew that an avulsed permanent tooth should be replanted. Furthermore, only 29.6% of teachers thought that they were able to distinguish between deciduous teeth and permanent teeth, whilst 20.4% correctly identified at least one of the appropriate mediums: milk, physiological saline or saliva, for storing an avulsed tooth. Teachers who previously received first-aid training with dental content or acquired dental injury information from other sources, scored significantly higher than teachers without such training or acquired information. CONCLUSION. The knowledge on emergency management of dental trauma among primary and secondary school teachers in Hong Kong is insufficient, particularly on the handling of permanent tooth avulsion and the appropriate storage medium for avulsed teeth. Receipt of first-aid training with dental contents and acquisition of dental injury information from other sources were positively correlated with knowledge in managing dental trauma.