The prevalence of conduct problems in children impacts upon families, educational settings, and broader society within Australia. Conduct problems develop early in an individual's life and can lead to more serious problems including substance abuse and delinquency in adolescence and adulthood. Given the high incidence of conduct problems in children, the need for prevention and early intervention strategies to target the onset and development of this phenomenon is paramount. This thesis focuses on early intervention strategies for reducing the incidence of conduct problems in children and explores a multi-modal early intervention and prevention program targeting children and families at-risk of the development of conduct problems. A randomised controlled trial involving 455 children was conducted to evaluate the efficacy of this program. Participants were drawn from ten Education Queensland primary schools in the Mount Gravatt district of Brisbane, Queensland, Australia. The 455 children were randomly assigned to either experimental or control conditions for the purposes of the program's evaluation. From this initial cohort, an indicated sample of 1 52 participants was identified through a universal screening process. This sample included children who were considered more at-risk of conduct problems. Participants designated to experimental conditions engaged in the school component of the program, with 66 of the experimental group receiving an additional indicated component facilitated in the school setting. Further, a selection of parents of children in the experimental group participated in the home component of the intervention. The retention rate for families engaged in the study was high with 96% of participants remaining engaged in the study throughout the evaluation process. The findings that emerged from the study revealed significant differences between participants who engaged in the intervention program compared with those designated to control conditions. Positive changes in the behaviour of students reported at the school level were statistically significant. However, while some changes were identified in the home setting, the treatment effects of the program were not significant. These findings were sustained at the six-month follow up period. Conclusions drawn from this study were conceptualised within the framework of current advances in the social science literature that focus on conduct problems and early intervention and prevention. The outcomes of the research emphasise the significance of comprehensive interventions programs for children and families at-risk that focus on both school and home settings and that are easily implemented in, and cost-effective to, community populations. Recommendations from this research serve to inform ftiture research agendas in early intervention and prevention and specialists in the fields of psychology and education.