Objectives: The study aimed to describe oral hygiene habits, oral hygiene status and gingival health in Flemish pre-school children and to explore factors associated with these clinical oral health variables. Methods: Cross-sectional data from 1,071 3-year-old and 1,119 5-year-old children from four geographical areas in Flanders (Belgium) were analysed. Buccal plaque accumulation and gingival health were assessed on six index teeth. Data on oral hygiene and dietary habits, oral health behaviour and socio-demographic variables were obtained through questionnaires. Results: 34% of 3-year-olds and 25% of 5-year-olds started brushing before the age of one, 17% of 3-year-olds and 23% of 5-year-olds brushed twice a day. Roughly, 30% of 3-year-olds and 37% of 5-year-olds presented with visible plaque accumulation. In both age groups, only 3 to 4% of children presented with signs of gingival inflammation. Multiple logistic regression models revealed that in both age groups children whose mothers had a college or university degree, had a smaller chance of presenting with visible plaque than children whose mothers had a lower educational level. With gingival health as dependent variable, multiple logistic regression analysis confirmed the major association between bacterial plaque accumulation and the presence of gingivitis. In the oldest age group, children’s former exposure to passive smoking was also significantly associated with gingivitis. Conclusion: Parents should be motivated to start brushing at an early age and brush thoroughly in order to maintain good oral health in their off-spring. Special attention should go to children raised by mothers with a lower educational level. Key words: Dental plaque, gingival health, gingivitis, oral hygiene, pre-school children, primary dentition.