Background Youth trends of physical fighting and abuse, motorcycle gangs, and rock throwing as a form of attack is dangerous and can cause injury. These growing trends are becoming more violent each year. A recent survey conducted at Khao Suan Kwang District, Khon Kaen Province in Thailand found that 600 people, the majority youth, were injured in 1 year due to violence. Traffic accidents were the main cause of injury, and bullying was a minor cause. Arnon's Model was, therefore, designed to reduce youth violence by using behaviour change process.

Methods Data were obtained from four phases in the Arnon Model. First, participants aged 15–25 years were selected based on their involvement in activities such as motorcycle and bullying gangs. Second, participants were trained as the military for 5 days to develop discipline and strengthen self-responsibility. Third, they were provided hands-on experiences to change their attitude, such as visiting prisoners or patients injured from accidents. Fourth, behaviour change was encouraged through community service volunteering.

Results Arnon's model was effective in changing behaviour amongst at-risk youth at Khao Suan Kwang District. Youth violence was reduced by more than 70%.

Conclusion The effectiveness of Arnon's model has been extended to 10 other provinces. It has also effectively reduced drug use among youth.