BACKGROUND: Little is known about the oral health of children under the age of four years. The determinants of early childhood caries (ECC) in this young age group are also not well understood despite a growing recognition that early interventions may deliver the greatest benefits. The aim of this study was to examine the oral health-related knowledge, attitudes and reported behaviours of parents of children aged 12-24 months living in rural areas of Victoria, Australia. METHODS: A robust theoretical model was utilized to identify oral health-related behaviours and their antecedent and reinforcing conditions within the context of this specific population group. Two hundred and ninety-four parent/child dyads were recruited through their maternal and child health nurses as part of a larger intervention trial. Parents completed a self-report questionnaire. RESULTS: Knowledge regarding risk and protective factors amongst parents was variable and sometimes at odds with contemporary evidence. Knowledge of the role of early infection with S. mutans was very low, with high levels of behaviours that may promote early transmission reported. Tooth cleaning was reported by most parents at least sometimes, however a large proportion lacked confidence and this was significantly related to the frequency of the cleaning. Parents were confused about the fluoride status of their water supplies. Most parents believed fluoride toothpaste reduced the risk of ECC but did not know whether it should be used with toddlers. CONCLUSIONS: The results of this study have implications for efforts to prevent dental decay in this very young age group. Health care professionals other than dentists need support to provide information and promote confidence with regard to optimal fluoride exposure. Attention should also be given to the contribution of early contact with particular bacteria in oral health education and promotion programmes.