Background The behaviour of young children receiving mildly invasive dental preventive procedures in a community setting warrants more extensive research due to limitations in the literature. Objectives To document the behavioural profile of preschool children undergoing a preventive oral health intervention (fluoride varnish application) and to investigate this behaviour across children with different previous experience of the procedure, ages and initial anxiety states. Method Nurse-child interactions were video recorded and child behaviours coded and analysed using a specially developed coding scheme (SABICS). Behaviour frequency was measured and presented diagrammatically, followed by independent sample non-parametric tests to distinguish behavioural group differences. Results Three hundred and three interactions were coded out of 456 recorded application sessions.Nonverbal agreement behaviour was observed most frequently compared to disruptive behaviours. Younger preschool children tended to exhibit interact with instrument behaviour more frequently than older children regardless of whether they had had previous application experience. Children who showed signs of initial anxiety were likely to display more disruptive behaviours during the later stage of the procedure compared with non-anxious children. Conclusions Dental staff working with preschool children are recommended to use encouragement-centred strategies to promote nonverbal cooperative behaviours in children. In addition, procedure instruments could be considered as a tool to gain child cooperation. Evidence of an autocorrelation effect of child behaviour was found, indicating that the early presentation of child behaviour predicted the behaviour of the child at later stages.