Parenting style may have a role in the development of young children's dietary behaviour, and a better understanding of parenting style may lead to better-targeted childhood obesity prevention interventions. This study aimed to investigate the association of parental self-efficacy, parenting style and dietary behaviour of young children. A cross-sectional study with 242 first-time mothers and their children was conducted using the data from the Healthy Beginnings Trial undertaken in one of the most socially and economically disadvantaged areas of south-western Sydney, in 2007-2010. Parental self-efficacy, parenting style (warmth and hostility) and children's dietary behaviours (consumption of vegetables, fruit, soft-drink and snacks) were assessed by face-to-face interviews with participating mothers in the control group when their children were 2 years old. Logistic regression analysis was conducted to examine the association between parenting style and the child's dietary behaviour. Mothers with higher levels of global parental self-efficacy and self-efficacy for an infant were more likely to report their children had 2 serves of vegetables per day, with odds ratio (OR) 2.40 (95%CI 1.35-4.27, P = 0.003) and OR 1.88 (95%CI 1.06-3.36, P = 0.03), respectively. A higher level of global parental self-efficacy or self-efficacy for an infant was significantly associated with having 2 serves of fruit per day with adjusted odds ratio (AOR) 2.46 (95%CI 1.35-4.48, P = 0.003) and AOR 1.85 (95%CI 1.00-3.41, P = 0.048), respectively, after adjusting for annual household income. Mothers with a higher level of parental warmth were more likely to report their children had 2 serves of vegetable per day with OR 1.85 (95%CI 1.06-3.25, P = 0.03). Parental self-efficacy and parenting style were associated, cross-sectionally, with important children's dietary behaviours. Interventions which target parental self-efficacy and parenting style may improve eating habits of young children, and contribute to childhood obesity prevention.