Objective: To understand current situation of the awareness of tobacco hazards among middle school personnel in Shanghai and to explore its influencing factors,and to provide reference for making targeted measures to control tobacco hazards in schools. Methods: A total of 30 middle schools in Shanghai were selected by stratified cluster sampling method. The questionnaires were used to investigate the smoking prevalence and tobacco hazard awareness of 3 007 faculty members. Results: The total smoking rate of school personnel in Shanghai was 8.25%; the complete correct rate on the harm of smoking and second-hand smoke was only 19.72% and 23.74%, respectively. The correct awareness rate of harm caused by tobacco, such as stroke, osteoporosis and heart disease, was less than 50%. Gender, education level, smoking behavior and tobacco control training were related with tobacco hazards perception level. Conclusion The smoking rate among middle school personnel in Shanghai has been generally improved, but the faculty and staff have an unbalanced understanding of tobacco hazards. The school's tobacco control education should be targeted. Smoking, men and personnel with relatively low education levels are the key groups in school tobacco control education.