Background: Non‐nutritive sucking habits, bottle feeding, and facial hyperdivergency have been suggested as the influencing factors of anterior open bite (AOB). There was inconsistent reporting of prevalence and a gap of knowledge in the literature. Aim: The aim of this study was to investigate the prevalence of AOB in 7‐ to 12‐year‐olds, with a special interest to characterise the determinants of this malocclusion. Design: A sample of 203 children aged 7 to 12 years were selected from a primary school in regional Australia. The legal guardian of each child completed a self‐administered questionnaire. Data were assessed using methods of univariate statistics and neural analysis. Results: The prevalence of AOB and thumb sucking was 24.1% and 23.2%, respectively. AOB was associated with the habit (correlation = 0.754) and duration (correlation = 0.574) of thumb sucking. Age, gender, birth order, feeding modality, sleep patterns, history of orthodontic treatment and tonsil, adenoid or grommet surgery, and parents’ level of education were not related to AOB (correlation absolute value ≤ 0.474). Conclusions: Thumb sucking, specifically for prolonged duration, increases the risk of development of AOB. Cessation of thumb sucking habits should be encouraged at an early age to avoid the development of AOB.