To quantify an anecdotally apparent increase in motorcycle-related injuries in children and adolescents across Victoria. Retrospective analysis of paediatric motorcycle injuries (1 July 2000 - 30 June 2004) from a statewide emergency department (ED) database (Victorian Emergency Minimum Dataset [VEMD]) and the Trauma Registry database at the Royal Children's Hospital (RCH), Melbourne. Trends in paediatric motorcycle-related injuries over time; patient demographics, circumstances of accidents (on or off road), and injury characteristics, including severity markers. The VEMD recorded 3163 patients aged < or = 16 years presenting to EDs with motorcycle injuries during the study period; population-based rates of these injuries increased by an average of 9.6% per year (95% CI, 6.2%-13.1%; P < 0.005). In the same period, there was a total of 167 motorcycle-related admissions to the RCH, increasing annually in line with statewide ED presentations. About a quarter of paediatric motorcycle accidents occurred in children aged under 10 years (VEMD, 22%; RCH, 27%) and most occurred off road (VEMD,89%; RCH, 71%). At the RCH, median length of stay was 3 days (interquartile range [IQR], 1-7 days) and the median Injury Severity Score was 9 (IQR, 4-10); 41% of patients required an operation, 13% were admitted to an intensive care unit, and two died. In Victoria, the incidence of motorcycle-related injuries is increasing in children and adolescents. Most of these injuries occur off road, outside of any legislative framework. There is an urgent need for coordinated legislative changes and educational efforts to decrease motorcycle injuries in children.