Objectives: To investigate the prevalence, trends, and characteristics of maltreatment and assault related hospital admissions and deaths among children; and identify common injuries and conditions associated with these admissions using routinely collected morbidity and mortality data. Methods: A retrospective cohort study of all children aged 0-17 years in Western Australia from 1980 to 2005 was identified from linked de-identified population level data. Annual trends in prevalence of assault and maltreatment related admissions were calculated and child characteristics were investigated using logistic regression models. Results: Assault admissions more than doubled from 2.8 per 10,000 children in 1981 to 6.1 per 10,000 in 2005 (p less than 0.0001) and maltreatment admissions rose from 0.7 per 10,000 children in 1981 to 1.3 per 10,000 in 2005 (p less than 0.0001). Males aged greater than 12 years were at greater risk of an assault, while children aged less than 6 years were more likely to be at risk of maltreatment as well as those from greater disadvantaged backgrounds. Aboriginal children were more likely to be identified with assault and maltreatment compared to non-Aboriginal children. Common indicators of assault admissions included injuries of the skull and facial bones, intracranial, wrist, hand, and abdominal injuries. Children with maltreatment-related admissions were more likely to have superficial head or abdominal injuries and a high proportion had infectious and parasitic diseases, particularly intestinal infections. Many of these cases were associated with factors influencing health status, particularly socioeconomic and psychosocial circumstances. Conclusions: There has been a steady increase in the prevalence of assault and maltreatment related admissions. Specific child characteristics and injuries associated with child assault and maltreatment-related admissions have been identified using routinely collected morbidity data and may be utilized as potential indicators for identifying and monitoring child abuse and neglect. Practice implications: Broadening child maltreatment surveillance to children's admissions for assault and maltreatment is an important public health initiative which can be improved by the increased use of external cause codes. Health data is collected using international coding standards enhancing comparability across states and countries and has clinical implications in highlighting injuries associated with child abuse and neglect. (Contains 2 figures and 4 tables.)