This study focus on the socio-psychological concept of self-esteem and examines its association with oral health behaviour and with some background variables that have been shown to be of importance in previous studies. In 1995, 3370 12-year-olds answered a questionnaire on social and demographic factors. Questions on attitudes and behaviour were also included. After reducing the number of variables and constructing new variables, multivariate analyses were performed. A polytomous regression on self-esteem showed that having very poor self-esteem as opposed to poor, good and very good self-esteem was associated with being a girl, not living with one’s biological parents, poor social support, having less interest in politics, poor adaptation in school and poor oral health behaviour. The results also showed that being a boy, choosing statements reflecting less exemplary behaviour, and being less well adapted in school increased the risk of having poor oral health behaviour, as did ethnic group affiliation and having poor self-esteem. Our results showed that self-esteem is a crucial intervening variable between variables measuring social background and outcome variables, especially oral health behaviour.