Dental caries is a common but preventable oral disease which, if left untreated, can result in the development of an abscess or the death of a tooth. Dental caries can have a significant negative effect on the health and well-being of children and young people, so it is vital that they are supported to perform and maintain effective oral hygiene. This article describes how dental caries develop and the risks associated with the disease and outlines some evidence-based strategies for performing effective oral hygiene and maintaining oral health. The author also considers the role of the children's nurse in various settings in promoting oral health and supporting children and families to perform and maintain effective oral hygiene.