Objectives:Previous studies have shown that sociodemographic factors are associated with adolescent toothbrushing. While there has been some investigation of parental modelling of oral health behaviour and the association between parental support and oral health, there has been no investigation of the home environment and its effect on oral health behaviour. The current study examines variables related to the family, including mealtime routines and family relationships to determine the best predictors of adolescent toothbrushing.Methods:Data from the 2006 Health Behaviour in School-Aged Children Survey were modelled using logistic univariate and multivariable modelling with outcome variable twice-a-day toothbrushing.Results:Higher family socioeconomic and affluence were significantly associated with greater odds of toothbrushing twice a day or more. Family structure was also significantly associated with girls' toothbrushing. However, under the multivariable model, eating breakfast was found to be the best predictor of twice-a-day toothbrushing among boys and girls. The next best predictor of boys' toothbrushing was eating family meals and of girls' toothbrushing, never going to bed hungry, followed by family affluence for both boys and girls. Under the multivariable model, family structure was no longer significantly associated with girls' toothbrushing.Conclusions:The study shows that the family and home environment should play a central role in the promotion of oral health, through mealtime routines, incorporating a fair parenting style and developing open and positive family relationships. Not only are these strongly associated with twice a day toothbrushing but, unlike sociodemographic factors, they may be relatively easy to adopt.