Youth violence is a global problem. The major research into youth violence has been conducted in the United States (U.S.) and there has been little research to investigate whether the prevalence or predictors are similar in comparable Western countries like Australia. In the current paper, analyses are conducted using two waves of data collected as part of a cross-national longitudinal study of adolescent development in approximately 4000 students aged 12 to 16 years in Victoria, Australia and Washington State, U.S.. Students completed a self-report survey of problem behaviours including violent behaviour, as well as risk and protective factors across five domains (individual, family, peer, school, community).Compared to Washington State, rates of attacking or beating another over the past 12-months were lower in Victoria for females in the first survey and higher for Victorian males in the follow-up survey. Preliminary analyses did not show state-specific predictors of violent behaviour. Therefore, the final multivariate model included the combined Washington State and Victorian samples. In the multivariate model, protective factors were being female and student emotion control. Risk factors were prior violent behaviour, family conflict, association with violent peers, community disorganisation, community norms favourable to drug use, school suspensions, and arrests. A major implication of these findings is that the range of factors that influence violent behaviour in North America may also apply in Australia. Hence, the application of U.S. early intervention and prevention programs may be warranted, with some tailoring to the Australian context.