Objective To realize the prevalence and main reasons of illness-induced absenteeism among elementary and middle school students in Shanghai during 2014-2015 academic year, so as to provide evidence for effective intervention measures. Methods Illness-induced absenteeism information was collected through surveillance system. Statistical description methods were used for describing the prevalence characteristics of absenteeism, and Chi-square tests was used for comparing gender and age differences of absenteeism rate. Results The illness-induced absenteeism rate during 2014-2015 academic year was 0.31%.  A total of 422 469 person-time were absent from school. The absenteeism rate was highest in winter, and boys and elementary students were more likely to be absent from schools. Most absenteeism were because of symptoms (90.76%), and fever and respiratory symptom were the main symptoms. And 2.70%, 1.54% and 5.00% were because of infectious diseases, injuries and other diseases. Reasons for absenteeism were significantly different between gender and school stages. Conclusion The illness-induced absenteeism surveillance system plays an important role in school health management. It is meaningful to exploit

the absenteeism information, to observe the absenteeism trends, and to complete warning system of infectious diseases.