OBJECTIVE: To examine comparable survey data across 10 years to assess whether rates of self-reported weapon carrying and intent to harm others have increased as suggested in reported trends in violent offences. DESIGN, SETTING AND PARTICIPANTS: Population-based surveys administered to Victorian secondary school students in 1999 (8984 students) and 2009 (10 273 students) attending government, Catholic and independent schools. MAIN OUTCOME MEASURES: Student self-reports of carrying a weapon and attacking someone with the intent to harm in the past 12 months. RESULTS: In both surveys, about 15.0% of students reported carrying a weapon and about 7.0% reported attacking someone with intent to harm in the past 12 months, with higher rates among boys than girls. There was no change over time in the rates of students carrying weapons or attacking someone with the intent to harm, after controlling for demographic variables. CONCLUSIONS: In contrast to media portrayals and reported trends in violent offences, rates of students carrying weapons and attacking others with intent to harm have not changed between 1999 and 2009. These findings underline the importance of having national population-based data to regularly monitor the rates of these and related behaviours among young Australians.