This is a cross-sectional epidemiological study comprising 840 randomly selected children in the age groups of 3, 5, 10 and 15 year-olds. All children were clinically examined for number of teeth, dental caries, dental fillings, plaque, gingivitis and probing pocket depth. Dental care and dietary habits were collected using a self-reported questionnaire. Among 3 and 5 year olds, 98% suffered from dental caries, compared to 91% of 10 and 15 year olds. The mean (SD) of decayed (initial and manifest) and filled tooth surfaces (dfs/DFS) in the different age groups was: 18.2 (14.1), 23.0 (15.4), 5.1 (4.2) and 6.9 (6.0), respectively. There was an average of ~ 30% in all age groups with plaque and gingivitis. Consuming milk with sugar more than 2–3 times a week (3 and 5 year olds) and eating sweets between principal meals twice a day (in 10 and 15 year olds) were statistically significant with caries prevalence. It is concluded that dental caries and gingivitis are significant public health problems among children in Da Nang, Vietnam.