Objective We investigated the incidence and seasonal patterns of child maltreatment hospitalisations in Hong Kong.

Design A retrospective study of subjects aged under 19 years with a primary diagnosis of child maltreatment admitted to hospitals in Hong Kong from 2001 to 2010. Data were retrieved from the centralised database of all 42 public hospitals in the Hospital Authority.

Main outcome measures Child maltreatment incidence rate.

Results A consistent seasonal pattern was found for non-sexual maltreatment in children aged 6–18 years (p<0.001). Hospitalisations peaked in May and October but dipped in August and January. No significant seasonal patterns were found for sexual maltreatment or among children under 6 years. The seasonal pattern of child maltreatment coincided with the two school examination periods. The annual child maltreatment hospitalisation rate in Hong Kong in 2010 was 73.4 per 100 000 children under 19 years, more than double that in 2001.

Conclusions A peculiar seasonal pattern and an alarming increasing trend in child maltreatment hospitalisation were observed in Hong Kong, which we speculated to be related to school examination stress and increasing socioeconomic disparity. Our findings highlighted differences in the trends of child maltreatment between Hong Kong and the West. Professionals and policymakers should be made aware of these trends and develop effective strategies to tackle child maltreatment.