Evidence-based parent-training programmes aim to reduce child behaviour problems; however, the effects of these programmes are often limited by poor participation rates. This study proposes a model of parent, child and family factors related to parental participation in parenting interventions. A computer-assisted telephone interview was used to survey parents of 4- to 7-year-old children (N = 2999). Logistic regression analyses showed that several parent and child variables were predictive of participation. In contrast, family variables, and other parent and child variables were not. Hierarchical multiple logistic regression showed that parental help-seeking behaviour and parenting style were the only significant predictors of participation. Mediation analyses found that help-seeking behaviour was a mediator between perceived child behaviour problems and participation, help-seeking behaviour was a mediator between parental depression and participation, perceived child behaviour problems was a partial mediator between parenting style and participation and parental depression was a partial mediator between perceived child behaviour problems and participation. Overall, the model was partially supported. The results extend previous research into parental participation in parenting programmes.