Background: Dental caries is a common disease and is acquired very early in children after teething. Primitive teeth play an important role in chewing, so oral disease will affect the physical development of children. The objective of the study was to investigate the current status of oral disease, the role of the mother and related factors of 3-5 year-old children.

Subjects and methods: A cross-sectional descriptive study of 524 children in some preschools in Hue city and their mothers. Clinical examination of the children’s oral health and interview with the mothers using to a set of questions.

Results: The rate of caries in 4 schools was 70.6%, plaque was 82.3%, gingivitis was 7.3%. with p>0.05. The average index of decayed, missing, filled teeth is 3.43, 0.19; 0.97, respectively; the decayed, missing, filled teeth index (dmft) was 4.59. The group of mothers with good knowledge and practice had children with lower caries (65.8% versus 75.7%, p<0.05). Dental caries increases in group of children eating sweets by 2.29 times (OR= 2.29; p<0.01), group with habit of sucking food by 1.76 times (OR=1.76; p<0.05), children brushing teeth only in the morning or evening had risks 2.27 times higher than children with the habit of brushing teeth twice (OR=2.27; p<0.001), brushing teeth without toothpaste or with salt had caries risks 4.36 times higher (OR =4.36; p<0.001).

Conclusion: The rate of dental caries in preschool children in Hue city is still quite high. It is necessary to strengthen the network of dental clinics in the community, strengthen communication and education on oral care