A self-directed variant of the Positive Parenting Program (Triple P) was evaluated using 63 preschool-age children at-risk of developing conduct problems. Families were randomly assigned to either Self-directed Triple P (SD), a self-administered behavioural family intervention program, or a waitlist group (WL). The 10-unit SD program teaches parents 17 parenting skills to increase pro-social child behaviours and decrease problem behaviours in home and community settings. Using mothers' reports of child behaviour and parenting practices, mothers in the SD group reported significantly less child behaviour problems, less use of dysfunctional discipline strategies, and greater parenting competence than mothers in the WL group. On measures of parental adjustment, there was no significant difference in conditions at post-intervention based on mothers' reports of depression, anxiety, stress and conflict with partners over parenting issues. Mothers' reports at 6-month follow-up indicated that gains in child behaviour and parenting practices achieved at post-intervention were maintained.